The 34-year-old said she hated herself so much, she would force herself to vomit every day because she felt so lonely in the band, reported Radar Online.
"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," she said.
The singer also said she felt embarrassed about her problem and didn't want to upset anyone by revealing how much she was struggling with the pressures of fame.
"'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."