"I think it took me some time to grieve about the things that have happened to me, and I couldn't be angry with myself for how long it took," said the musician and actress, who graces the cover of the magazine's May beauty issue.
The "Stupid Love" singer, 34, may have maintained a fearless image in public, but behind the scenes her psychological anguish grew so intense, it caused her crippling physical pain, which was eventually diagnosed as fibromyalgia.
"I've been depressed and been at the grocery store and seen photos of myself and gone, 'Well, I look like everything is good.' But I was secretly freaking out, and the world had no idea," she shared. "Or some people in the world. I hate using that phrase 'the world.' It's so egocentric to assume the whole world thinks about or knows about me. It doesn't."
Gaga now adheres to a treatment plan that includes medication, meditation, radical-acceptance therapy and self-care, and told the magazine she's feeling the best she's felt in years.
Though she's already won 11 Grammys, a BAFTA and an Academy Award — and launched her own beauty company, Haus Laboratories — Gaga still has big plans for her future. Including? "Marriage," said the star, who's currently dating tech entrepreneur Michael Polansky.
She also told the magazine she'd like to one day be a mom.
"I will say I am very excited to have kids," she shared. "I look forward to being a mom. Isn't it incredible what we can do? We can hold a human inside and grow it. Then it comes out, and it's our job to keep it alive."
"It's so funny," she added, "everyone works out of my house every day. When they come in, I always say, 'Welcome to the Womb!'"