Cheryl Cole has said that Simon Cowell was right to dispense with her services as a judge on the X Factor US as she was not in a good place in her life at the time.
In an interview in the new issue of Elle magazine in the UK, Cole says: "I can talk about this because I'm OK about it now. But I went through hell and it literally drove me mad."
She continues: "I became so desensitised, you could say terrible things to me and I wouldn't even think about it.
"I'd read awful stuff about myself and not blink. I shut down because I didn't know what else to do.
"Now I can say that Simon was right to get rid of me."
Cole adds: "I wasn't well in the head when that was going on, so it wasn't going to work. But he wasn't right not to tell me to my face."
The singer says that after she was dropped from the show she sent Cowell an expletive-filled text telling him she hated him.
Cole, now back as a judge on X Factor UK, also says she felt as if she was having a nervous breakdown last year.
"It only hit me at the beginning of 2013 that I'd completely lost myself. I'd look in a mirror and think: 'Who the hell is she?'," she says.
"I didn't know what I thought or felt about anything, couldn't make decisions - I didn't even know what to eat or drink.
"Something was seriously wrong: it felt like a nervous breakdown."
She continues: "I had to stop, get out of my life I'd been living and find myself again. The consequences if I didn't were just too frightening."
Of coming through the experience, she says: "I'm just enjoying finding out who I am. That's good enough right now... I know I'm really lucky because none of what I've been through broke me."
"It actually taught me everything I'm going to need for the rest of my life," she says.