The 34-year-old singer says she hated herself "so much" she would force herself to vomit "every day" because she felt so lonely in the band.

She said: "I just hated myself. 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.

"I did it every day 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."

Nicole felt "embarrassed" about her problem and didn`t want to upset anyone by revealing how much she was struggling with the pressures of fame.

In an upcoming episode of `VH1 Behind the Music`, she said: "`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.

"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"

A clip for the programme also showed relatives of the singer - who quit Pussycat Dolls two years ago - revealing she had to "get help or die".

The show airs in the US on October 7.
sections: Celebrities