On May 7, Tiffany Haddish will unveil her new book, "I Curse You With Joy," which publisher Diversion Books described as a collection of essays that “lay it all bare, bringing readers into Tiffany’s inner circle where joy, honesty, humor, and heart are the order of the day." Ahead of the release, she spoke about a personal battle in an interview with PEOPLE that was published earlier today (April 25).

Recently, the comedian learned that she's been suffering from endometriosis, a disease in which tissue grows outside the uterus. "I'm pretty sure the devil is real because the first day of my period, no matter what, the devil goes into overdrive," Haddish said. "I feel like my life gets turned upside down."

The Haunted Mansion star told the publication that she found herself making a doctor's visit in November 2023 due to fainting. "She gave me something because I kept passing out," Haddish explained. "I don't talk about it, but people just think I'm sleep everywhere, but I'm passing out because I'll be in so much pain. The pain is crazy. It feels like somebody is kicking me in my back."

Previously, Haddish was told that she had "a dent in my uterus." "It turns out it's not a dent they saw on the ultrasound. It was endo that was hanging down,” she stated. “It looked like a dent, but it was just extra layers."

Haddish revealed that she's suffered eight miscarriages due to the affliction, the most recent of which happened in 2023. "Every time I find out I'm pregnant, I’m like, ‘Don’t drink, don’t smoke, don’t do nothin'.’ Even if I don’t really want [the baby], I still try to give it a chance," the Los Angeles, CA native admitted. "It's like, I won't know why there's so much blood. And then I go to the doctor and they're like, 'Oh, you're miscarrying right now.'"

These days, Haddish is feeling better thanks to hormone medication, which makes her “feel drowsy.” “But I've been working out even more,” she said. “And I've gone from 11 days [on my period] to four or five, which is kind of normal, so that's nice."