Nicole Scherzinger arrives at the X factor conference at Corinthia Hotel London on August 16, 2012 in London, England. Credit: Ben Pruchnie/Getty Images

Nicole Scherzinger was suffering in silence during her seven years as the Pussycat Dolls' lead singer.

In her VH1 Behind the Music special (airing October 7), the 34-year-old singer opens up for the first time about her struggle with bulimia.

"It's embarrassing. I never spoke about it. Like I said, I never want to play a victim, and I never wanted my family to hear about things from me because I think it would break their heart, you know," Scherzinger says. "I guess it was like my addiction, right? 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. My bulimia was my addiction; hurting myself was my addiction."

Scherzinger -- who released her debut solo album, Killer Love, in 2011 -- says she "did it everyday for, like, years. 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."

The Hawaiian-born, Kentucky-raised musician joined the Pussycat Dolls in 2003 following the success of the burlesque troupe of the same name.

During her revealing chat, Scherzinger also estimates she "probably did 95 percent" of the singing "on my own" for the girl group's 2005 debut album, PCD. "I hope I don't get in trouble for the stuff that I say," Scherzinger says, "but I'll never forget I finished the album, PCD, and [executive producer Ron Fair] and I brought the girls into the studio and we played it for them. It was the first time they'd ever heard the music."

Despite the hardships she sometimes faced, Scherzinger -- who first found fame as a member of the made-for-TV band Eden's Crush -- says ex-bandmates Melody Thornton, 28, Ashley Roberts, 31, Kimberly Wyatt, 30, Jessica Sutta, 30, and Carmit Bachar, 38, are "like my sisters."

Scherzinger's Behind the Music airs Sunday, October 7, at 9 p.m. EST on VH1.