Mandy Teefey Says Daughter Selena Gomez Was 'Proud' of Her for Sharing About Recent Health Crisis

Mandy Teefey was a vision of happiness while shooting the December cover of Entrepreneur magazine with daughter Selena Gomez and Newsette founder Daniella Pierson in support of their new mental health company, Wondermind.

But behind her big smile, she was struggling.

"I almost passed out doing the shoot," Teefey, 45, tells PEOPLE in this week's issue, on newsstands Friday. "We had to break so many times, but all my friends and loved ones around me helped me get through it. I was smiling and laughing most of the time because I was going to faint. Don't judge how someone looks because you don't know what's underneath that picture."

Less than a month before the shoot, Teefey had been hospitalized with life-threatening double pneumonia that she says had been "exacerbated" when she caught COVID-19.

"I got pneumonia in February in New York, and I guess the doctor didn't really clear it up as much as it needed to be," she says. "I had gotten IV vitamin therapy, which I think helped me get through the times I did."

"Then a week before I was going to get my first COVID shot, I got COVID," she continues. "I was at home the whole time. When my fever broke, my oxygen went to 69, and I was rushed to the hospital. The first hospital was pretty badgering, like, 'Why didn't you get your shot?' I'm like, 'I literally can't breathe right now. Can we talk about this later? I will explain why.'"

Teefey says she was then transferred to Cedars-Sinai hospital in Los Angeles, where they gave her steroids and antibiotics, as well as breathing exercises to do.

"They said that had my body not responded as quickly as it did, I had two days [to live]," she says. "They said, 'We don't know how you've been breathing this whole time.' I had, like, half a lung. I made it through COVID and didn't lose my taste or smell or anything, but it beat up my lungs pretty hardcore."

The silver lining of it all, Teefey says, is that she was able to come up with the name Wondermind for her new company while in the hospital.

"Something positive came out of it," she says. "It was definitely an experience, and it wasn't scary until I got home. When I got home, I was like, 'Wow, I may not have ever come back here.' I was a lucky one."

RELATED VIDEO: Selena Gomez Hopes She 'Can Help Others' with Mental Health Initiative Launched with Rare Beauty

Though the shoot was so soon after her hospitalization, Teefey pushed herself to do it. But when the photos came out, she felt the need to speak out about her hospitalization after she was criticized for her weight gain from it.

In a Nov. 19 Instagram, Teefey posted a screenshot of a DM she had gotten offering her a weight-loss program for $5,000 and explained that her hospitalization caused her to gain 60 pounds.

"I posted because I wanted to be like, 'Guys, this is why you don't judge people,'" she says. "I did not expect it to get picked up at all by anybody because I'm like, 'Nobody cares about my Instagram.' I was like, 'Oh my gosh, I'm embarrassed. It's scrolling on CNN.' It's really hard for me to have that kind of attention. But Selena was like, 'No mom, I'm proud of you.'"

Ever since Gomez, 29, became an international star in her early teens, Teefey says she's learned to stop paying attention to comments on social media.

"I used to read DMs for entertainment because some of them are pretty creative," she says. "There are some really creative writers out there! I've stopped reading them, and I debate on whether turning my comments off or not because I sometimes reply, and I'm not mean, but I'm kind of a smart-ass. The comments will be like, 'Do you know what you've done?' And I'm like, 'Can't wait for you to tell me!'"

"I hate wasting my time on social media," she adds. "That's why I only have Instagram. It's the smartest thing for me because I had Facebook for two months and was arguing with people who made no sense. I'd rather just talk to them in person, have a drink of an old-fashioned and get into the deep conversations."

When Selena was only 14, Teefey says she'd get death threats.

"I answered one time and then the girl went, 'Oh my gosh, I'm your biggest fan,'" she recalls. "They're just trying to get your attention. One thing I don't agree with therapy is that no one can make you feel a certain way. I don't agree with that, otherwise, bullying wouldn't affect people. I get the meaning behind it and that you're in control of your feelings, but if you're getting beat down, you can only be so strong. It took me until I was 40 to finally go and get the help that I really needed. I don't want people in their 20s to wait until they're 40 and lose a couple of great years that they could have had."

Teefey's mental health journey dates back to when she got pregnant with Gomez at 16 years old.

"I feel at that moment, something changed in me," she says. "I was too young to be giving birth or pregnant. It changes women's hormones, and I started having ups and downs. I didn't understand it because I didn't grow up in a neighborhood where you talk about feelings. It was just like, 'You're crazy.'"

While growing up in Texas "we would sit on the front porch and watch the drug dealers and the hookers, and that was entertainment," Teefey says. "So nothing was bizarre. I didn't know therapy existed."

RELATED VIDEO: Selena Gomez on Sharing Her Struggles to Help Others: 'I Want People to Know They're Not Alone'

Then in her 20s, Teefey says she would "start crying" out of blue and "always felt out of place" no matter where she was.

"I had this insecurity, and I noticed none of my friends ever acted the way I did," she says. "So I, on my own, researched therapists. I probably went through about 15 when I was in Texas, because one of them interviewed me — I'll never forget this — and they were like, 'Do you see things?' I was like, 'What do you mean, do I see things? I mean, I saw a black butterfly the other day.' And he goes, 'Oh, you're hallucinating.' He gave me medicine for it and had me thinking I was hallucinating."

"That wasn't the case," she continues. "It was just the black butterfly on my windshield! But I didn't understand what to say to a therapist. So I've probably been on every medication under the sun."

Right before Teefey moved her and Gomez to L.A., she found a doctor in Dallas who told her she was bipolar and put her on anti-seizure medication.

"I learned everything I possibly could about bipolar to understand how to be a better person and how to live with it," she says.

Everything changed though when she started work as an executive producer on the first season of the Netflix series 13 Reasons Why in 2016.

"When 13 started, I started going through early menopause, and my hormones were changing," she says. "I started having grand mal seizures, and I was on anti-seizure medication. The doctors I found in L.A. had me on medications that countered each other, so I went, 'My anti-seizure medication is causing seizures.' And I'm talking about seizures where my husband thought I was dead after it was happening."

Right before the second season of 13 was set to start filming in 2017, Teefey knew she wasn't in a good place.

"I couldn't sleep, and one night I took more than I was supposed to take of my medication to go to sleep," she says. "I was wide awake, and I woke up my husband, like, 'Something's wrong. I got to go somewhere.'"

Later that day, which was set to be the first table read for the show, Teefey called her showrunner and told him she wasn't going to make it.

"I said, 'I'm going to go practice what I preach,'" she says. "So I went away for 30 days, and they took the time to run all the proper tests. They detoxed me from all the medications, and I had a therapist and a psychologist in groups and all this art therapy. It was something that was just really amazing for me to understand who I was."

At the treatment center, Teefey was told that she didn't have bipolar, but rather attention deficit hyperactivity disorder (ADHD).

"I started reading on ADHD at 40 trying to figure out what was best for me, and how I needed to restructure my mind," she says. "I think part of what made Wondermind so interesting to me was that the facility I went to was $1,500 a day. My insurance covered it, but a lot of people were getting kicked out because their insurance was kicking them out. If I wouldn't have had access to those tools, would I still be here? What kind of life would I have?"

Now, Teefey — who manages her own ADHD by taking medication whenever she feels she needs it — is proud to offer tools and content to help people with their mental health regardless of their income or insurance through Wondermind, which will fully launch in February.

"We're not here to diagnose people, but we have an advisory board to make sure all our content is as relatable as possible while following the scientific, proven tools that actually work," she says.

The idea for Wondermind was born during an interview Teefey and Gomez (who has been open about her bipolar diagnosis) did with Newsette founder and CEO Daniella Pierson.

"It was one of the first interviews me and Selena had done about our personal mental health, and how it affected each other and our relationship," she says. "Daniella's questions were so inquisitive and thoughtful on the matter that it put us in a place we had never been together. By the end of the interview, me and Selena were like, 'We feel closer to each other.'"

Afterward, all three women kept in touch and decided to build a company that focused on mental health and teaching people about mental fitness.

"For us, what mental fitness means is working with your mind each day," Teefey says. "I like the way Daniella explains it. She says that if you had a personal trainer, you couldn't not work out during the week and expect a six-pack. Well with therapy, if you can't afford one hour a week, what tools do you need to [help your mind]? So what we're trying to do is have tools and podcasts and content that can help people understand the way different people's minds work."

Teefey and the Wondermind team are also focused on creating tangible products to help with mental health, including a die that can be used by those with ADHD.

"With ADHD, they try to get you to use these big old-timers, so you don't get distracted on doing your task," she says. "We want to create them as dice where you can put them in your pocket and then you shake it, and they're cooler looking. It's easier to carry around and not something that somebody's going to come up and go, 'Oh, what is this?' And then you have to tell your personal story if you're not ready to tell your personal story."

RELATED VIDEO: Selena Gomez's Mom Mandy Teefey Talks 'Pinch Me' Moment While Executive Producing '13 Reasons Why'

One of the podcasts that will be offered through Wondermind will be hosted by Teefey, who says her dream guest is comedian Bill Burr.

"With the podcasts, we are just going to have conversations that are so laid back, like you're listening to a friend," she says. "We're going to focus on everyone from young kids to teenagers to adults to men and women. It's for everyone."

At home, Teefey makes sure to create an open environment with her 8-year-old daughter Gracie (whom she shares with her husband Brian).

"We're very open with her," she says. "I recently had a big mom proud moment. We watch Schitt's Creek nonstop at my house, and she had a friend over, and they were playing in my makeup set. During the Schitt's Creek episode that was on TV, David and Patrick kissed and Gracie's friend, who is very young, was just like, 'Ew.' Gracie goes, 'What? They just kissed. They love each other.' Then the friend said, 'Well, would you kiss a girl?' And Gracie goes, 'Well, no, but that doesn't make them weird because that's not who I love. They can love whoever they want.'"

"Then the other girl was like, 'Oh yeah, I guess that makes sense,'" she continues. "They moved on, and I was like, 'Why can't adults do that?'"

Teefey admits though that it sometimes "scares" her how smart Gracie is.

"She's a little hustler with money," she says with a laugh. "Like with cash, she'll charge interest if we borrow it. If we need parking, and she has money, she'll be like, 'You know, you're going to have to owe me 5 percent.' I'm like, 'OK, fine.' I didn't even know what $5 was at her age! Then all her friends order sushi, and Selena's like, 'What about McDonald's when I was your age?' They're like, 'I want Tuna Carpaccio.' How do you know that?! It's a whole different lifestyle than I had or Selena had."

Since Teefey was adopted, she had no warning about her ADHD diagnosis. But with Gracie, Teefey knows exactly what to look out for.

"She's not in therapy or anything, but we do extra tutoring for her and make sure that she's getting everything she needs because there's a huge possibility she may get it when she gets older," she says. "ADHD and bipolar are often misdiagnosed with young girls, so the fact that I know my genes, that can help us guide her in the right way. But I like her spirit, and I'm enjoying it."

As she looks toward the New Year, Teefey says she can't wait to see what Wondermind becomes — and how it will help people and their families.

"[For a time] health put tension on Selena and I's relationship, with me not understanding my situation, and her not understanding hers," she says. "So we were going through the ups and downs. To be able to maybe bring families together makes me feel so blessed."

For all the details on Mandy Teefey's health crisis, pick up the latest issue of PEOPLE, on newsstands everywhere Friday.