However, the 34-year-old says she feels more confident that ever in her 30s, reported Daily Star.
The 'Poison' star, who battled with bulimia when she was in girl group, said she felt like two different people because she had to constantly appear confident and sexy even though she was unbelievably insecure underneath it all.
"I spent 10 years - the whole time I was in the Pussycat Dolls - as two people, one on stage and then behind closed doors. I was this girl who was lost and lonely, hating myself.
"Just because you wear a corset and dance doesn't mean you think you are beautiful. I was unbelievably insecure and I couldn't control it. My metabolism was all messed up. I was losing the one thing I only ever wanted to do - sing. I saw therapists, psychiatrists, life coaches and dealt with it head on," she said.
The pop star, who is currently in the UK for her role as a judge on 'The X Factor', has now overcome many of her issues and feels more secure in herself than ever.
