Demi Lovato suffered three strokes and a heart attack, her upcoming YouTube documentary revealed. It will give a glimpse of her journey after her 2018 overdose and will also show how she had to "essentially die to wake up."

Ahead of the premiere of her documentary "Demi Lovato: Dancing With the Devil," the 28-year-old pop star sat down for an interview with CBS Sunday Morning and shared what was going on her mind during her onstage comeback.

It was just last year that she returned to the stage for the first time in almost two years since the overdose.

"I didn't know if I'd ever step foot on a stage again. When I woke up in the hospital, I was like, I don't know the full extent of the damage that's been done. I hadn't tried singing yet," she said.

Lovato had been battling substance addiction but it was in July 2018 that she was hospitalized after drug overdose at her Hollywood Hills home. Back then, doctors told her she would have had about five to 10 minutes to live had no one called 911.

"If no one had found me, then I wouldn't be here. I'm grateful that I'm sitting here today, yeah," she said on the show.

"For the first time in my life, [I] had to essentially die to wake up," added the "Heart Attack" hitmaker, who spent almost two weeks in a hospital before undergoing treatment at a rehab center and sober living facility.

About her path to recovery, she's not completely given up on all substances. She still smokes weed, which is legal in California, where she lives, and drinks alcohol "in moderation."

"I think that the term that I best identify with is 'California Sober,'" Lovato said.

"I really don't feel comfortable explaining the perimeters of my recovery with people because I don't want anyone to look at my perimeters of safety and think that's what works for them because it might not."

"I am cautious to say that, just like I feel the complete abstinent method isn't like a one-size-fits-all solution for everybody. I don't think that this journey of moderation is a one-size-fits-all solution for everybody, too," she added.

The first part of the four-part documentary "Demi Lovato: Dancing With the Devil," will premiere on YouTube on March 23.

In the documentary, Lovato also revealed that she lost her "virginity in a rape."

"We were hooking up but I said, 'Hey, this is not going any farther, I'm a virgin and I don't want to lose it this way.' And that didn't matter to them, they did it anyways. And I internalized it and I told myself it was my fault because I still went in the room with him, I still hooked up with him," said Lovato, who starred in Disney Channel movie "Camp Rock" when she was just 15.

"I was a part of that Disney crowd that publicly said they were waiting till marriage. I didn't have the romantic first time with anybody, that was not it for me and that sucked. And then I had to see this person all the time, and so I stopped eating and coped in other ways: cutting, throwing up, whatever. And my bulimia got so bad that I started throwing up blood for the first time," she added.

demi-lovato After tweeting a prediction 10 years ago, singer Demi Lovato wishes materialized into reality during the Super Bowl LIV. REUTERS/Danny Moloshok