Joshua Bassett on Surviving Childhood Abuse and a Near-Fatal Health Crisis: 'I Felt My Heart Failing'

"Peace is the only path that leads you home."

That's the quote that greets Joshua Bassett anytime he unlocks his iPhone, a gentle reminder to always take stock in how he's feeling.

"If I look at my last year, the difference between the good days and the not good days comes down to whether I took time for myself," the High School Musical: The Musical: The Series star tells PEOPLE in this week's issue, on newsstands Friday.

In this past year Bassett, 21, found himself at the center of intense public scrutiny when his HSMTMTS costar Olivia Rodrigo released her viral hit "Drivers License" last January.

The song is widely believed to be about their alleged breakup, though neither has ever confirmed a relationship. Bassett says the stress from the hate he received — including death threats on social media — hit him hard. Then, after several days of feeling ill, he wound up in the hospital battling heart failure.

"In this last year a lot of my biggest fears came true," he says. "But in that, I found that I'll always be OK, if not better off."

RYan Pfluger Joshua Bassett

In the week leading up to his hospitalization, Bassett says "every day I felt worse and worse."

"I was sleeping 16 to 20 hours a day," he says. "I couldn't even stand up for longer than 30 seconds."

Six days after "Drivers License" debuted, Bassett dropped his song "Lie Lie Lie," which he says had long been scheduled for release on that day despite speculation he had written it in response to Rodrigo's hit.

But instead of feeling excitement about his new single, "I felt my heart literally failing," says Bassett. "I was like, 'This isn't just anxiety. This is bad.'"

RELATED: Joshua Bassett Reveals Near-Fatal Septic Shock and Heart Failure Led to His January Hospitalization

At his insistence, a HSMTMTS producer took him to the hospital, where he was diagnosed with septic shock.

"The doctors were like, 'If you hadn't checked in within 12 hours, you would have died in your apartment,'" says Bassett, who was also told his illness could have been brought on by stress. "It's wild that I was this close to taking another nap."

Nine days later, Bassett left the hospital physically recovered but mentally adrift.

"I was even more depressed and stressed," he says. "I had a panic attack every single day."

Watch the full episode of People Features: Joshua Bassett on PeopleTV.com or on the PeopleTV app.

He wrote his trio of lyrically revealing songs "Crisis," "Secret" and "Set Me Free" during this time, and while one would assume making music would have been therapeutic, he says it was actually "stressful and hard."

"People had this mentality like, 'Oh, you were going through so much, so what you were making must have been so great,'" he says. "While, yes, I was able to make something out of my pain, a lot of times it was just me grieving and going through all these different feelings."

Bassett says he decided to hold off releasing the songs until December to avoid fueling rumors. But after the release, "that week was worse than the year combined," he says. "I got what I had to say off of my chest, but it brought all that stuff back up, and the healing isn't very linear."

Bassett credits his therapist, along with yoga and meditation, with helping him find his footing.

"My therapist, she loves the song 'Set Me Free,' but every time she hears it, she goes, 'Only you can set yourself free,'" he says. "I'm like, 'Yeah, yeah, yeah, I get it. I get it.' But I do understand now that it really is me who can give myself permission to move on. Ultimately, I was the one who had to set myself free."

In his sessions, he was also finally able to process the trauma stemming from the sexual abuse he had endured as a child and as a teen. (Bassett hasn't publicly named his abusers but previously said a relative abused him from ages 5 to 9 and that an older man in one of his theater groups abused him when he was a teen.)

"What I realized recently is that the reason why I haven't been able to process so much of it is because I went into pure shock," he says. "I'm still very much in the middle of the whole process, and I think it is a lifelong thing, but I'm learning to peel back the layers."

RYan Pfluger Joshua Bassett

Bassett hopes that by sharing his story, he can help others.

"It really bothers me that people said, 'Why didn't you do anything about it?'" he says. "When you go into freeze mode, you literally shut down. If I, a person with a platform, got treated like that, what would happen to a person in a small town? I won't shut up about this until we're far past that."

HSMTMTS showrunner Tim Federle says that even while Bassett's "public persona has exploded in the last several years," he's "growing into somebody who pays less attention to 'the comments,' and more attention to putting good into the world."

"He has a complex backstory, and I think he's choosing the challenging-but-noble road of forgiving, accepting, and rising above the noise to make the world a better place with his art and his attitude," Federle says.

RELATED: Joshua Bassett Faces Lingering Feelings for an Ex in 'Doppelgänger' Music Video

Now Bassett is ready to usher in a new era. He released his latest single, "Doppelgänger," in February. And he hopes to spread a positive message with his new Disney + film Better Nate Than Ever (streaming April 1 and written and directed by Federle), about a boy who runs away from home to New York City to pursue his Broadway dreams.

"We filmed Better Nate Than Ever during a period when Joshua was receiving quite a bit of online speculation and trolling. This was all on the heels of a health scare that had Joshua in the hospital fighting for his life," Federle says. "At a moment when many people would have become jaded or embittered, I watched Joshua start a serious meditation practice, double down on his songwriting, and mentor the two young teenagers who starred opposite him in the film."

20th Century Studios Joshua Bassett and Lisa Kudrow in Better Nate Than Ever

At the end of the day, Bassett says, "Everything I do aligns with what I needed when I was 10."

"With that, I'm constantly seeking how can I have a greater impact on myself and others, whether through music, charity or projects," he says. "My mission is to bring light to people and help them find their peace. That's all I ever want to do, truly."

For all the details on Joshua Bassett's story of survival, pick up the latest issue of PEOPLE, on newsstands everywhere Friday.