The former Pussycat Doll opened up about her body issues in an interview for VH1's Behind The Music, which is due to air this weekend.
"I just hated myself," she said of her time in the all-girl group. "I really was so disgusted with myself, and so embarrassed. I felt so alone. I was in a group, and I never felt so alone in my life."
The 34-year-old star admitted that instead of turning to drink or drugs, she got into the habit of making herself sick after performances.
"I guess it was like my addiction, right?" she explained. "I never did drugs, but kinda doing things to myself was my addiction.
"It's like when I got off stage, I was on this high, and I'd come back to my room and I'd be alone, so I would just do things," she added.
"My bulimia was my addiction. Hurting myself was my addiction."
Scherzinger - who left the Pussycat Dolls in 2010 to launch a solo career - also revealed that she hid her illness from her bandmates.
"I did it every day for, like, years," she said. "Every time I had a second to be alone, I was doing something to myself.
"You get, like, blisters on your hands or scars on your hands, and I'd try to hide those. I think the girls could tell."
During the VH1 special, the X Factor judge also confessed that she sang "95%" of the bands vocals.
"I love those girls, they're like my sisters," she said. "But people don't even know the story. They have no idea."
She added: "I was in the centre because I was singing. I was the [only] one singing."
Nicole Scherzinger's episode of Behind The Music airs October 7 on VH1. Watch her talking about her time in the Pussycat Dolls below: