How Brandi Carlile Got Into a 'Better Headspace' After Road Life Struggles: 'Take the Rest'

In 2018, Brandi Carlile was riding high on the success of her highly acclaimed sixth studio album By the Way, I Forgive You. But behind the scenes, she was struggling.

In this week's issue of PEOPLE, on newsstands Friday, the Grammy-winning singer-songwriter, 39, gets candid about how she abused steroids and sleep aids during that time — and for years prior — to help her make it through her rigorous touring schedule as she dealt with recurring cysts on her vocal cords.

"I had a problem. And the problem is that I thought that sedating myself was normal," Carlile says. "The way I traveled and the way I navigated this country was with the help of a lot of sleep aids. All my friends were doing that to sleep on tour buses and on planes so they could get up and go to the radio stations. No one told me that it wasn't normal or that accidents can happen."

Carlile recounts the scary moment she almost had an accident herself in her new memoir, Broken Horses (out now). While alone in her hotel room during a three-show run at the Beacon Theatre in New York City in April 2018, Carlile almost accidentally took six Xanax instead of the steroids she was prescribed.

"I suddenly realized with a shot of adrenaline and shame that I was staring down at six Xanax that I was about to pop into my mouth and go back to sleep," she writes in the book. "I don't know if I would have ever woken up."

Carlile goes on to say that "no amount of defense" by her wife of nearly nine years, Catherine Shepherd, or her bandmates, Phil and Tim Hanseroth, "would have been enough to remove the stain left by a simple accident."

"Just a tired mom alone in a hotel room afraid to let anyone down and wanting the show to go on," she writes. "I will always think about that before I pass judgment on a person who's had a drug overdose."

After that moment, Carlile realized she needed to get help. As she approaches her 40th birthday in June, she says she's now in a "better headspace" than ever before thanks to her wife, their daughters Evangeline, 6, and Elijah, 3, and the counselor who helps her stay healthy.

"I say no now," she says. "I will cancel things now. If I'm sick, I will not take steroids and play a show and hurt my voice that I depend on, that so many people depend on."

By being candid about her own struggles, Carlile — who kicked off her Broken Horses virtual book tour on Tuesday — hopes she can help other musicians.

"These things are weird, complicated, hard to talk about, embarrassing and a really big part of being a musician and touring," she says. "There are a lot of people that work around you who will tell you that the world stops turning if you take a rest, if you cancel the show because you're sick. Cancel the show. Take the rest. Avoid some of the paths I went down."

For all the details on Brandi Carlile's struggles, pick up the latest issue of PEOPLE, on newsstands everywhere Friday.