Tiffany Haddish Reveals Painful Endometriosis Battle and 8 Miscarriages: 'The Devil Is Real’ (Exclusive)

Amid numerous struggles in recent years, Tiffany Haddish has been grappling with grueling pain.

"My body be playing tricks on me," the comedian and actress, 44, tells PEOPLE exclusively in this week's issue. Ahead of her no-holds-barred new memoir I Curse You With Joy, out May 7, the star opens up like never before about her reproductive health battle and the heartache it's caused.

"I'm pretty sure the devil is real," says Haddish, "because the first day of my period, no matter what, the devil goes into overdrive. I feel like my life gets turned upside down."

She also experiences debilitating pain, which she only recently learned was likely due to suffering from endometriosis, a condition where the endometrium extends outside of the uterus and can result in pelvic pain. "I'm be like, 'Am I dying?'"

In November of last year, Haddish says she visited her doctor because she was fainting. "She gave me something because I kept passing out. 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," she explains. "It feels like somebody is kicking me in my back." Though she's powered through extra heavy painful periods for years, Haddish says she was previously told she had "a dent in my uterus." She only recently learned that the diagnosis was incorrect.

"It turns out it's not a dent they saw on the ultrasound. It was endo that was hanging down. It looked like a dent but it was just extra layers."

To address the issue, "they've shaved it down, I had to do a fibroid [removal] thing," she says. At this point, "I just want them to stay out of [there]." Still she says that the most painful experience, and potential side effect, of endometriosis has been pregnancy loss.

"It's so f---ing devastating," she says, revealing she's had a total of eight miscarriages. Haddish, who was married once and last linked to rapper Common, is known for being sex-positive and telling expletive-laden jokes about her busy love life. But when it comes to pregnancy she takes it very seriously.

"Every time I find out I'm pregnant, I’m like, ‘Don’t drink, don’t smoke, don’t do nothin’," she says. "Even if I don’t really want [the baby], I still try to give it a chance.”

Her last miscarriage was just last year. "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. And I just D&C (dilation and curettage, a procedure to remove pregnancy tissue)".

Haddish is currently celibate though dating "multiple guys." She’s not completely sold on getting married again or becoming a mom, but “there is a part of me that wants to,” she says of the latter. “I’ve got all this love, I should give it to somebody who can grow with it.”

As for how she's feeling these days, "The last two months have not been as bad," she says. Prescribed hormone medication, "I just feel drowsy. But I've been working out even more. And I've gone from 11 days [on my period] to four or five, which is kind of normal, so that's nice."