Kesha admits checking into rehab was the ''scariest'' day of her life.

The 'Tik Tok' singer spent two months in a rehabilitation centre being treated for an eating disorder this January, and says she cried incessantly after her mother dropped her off and worried what people would think of her.

The 27-year-old star recalled to Britain's ELLE magazine: ''The first day at the treatment centre was the scariest of my life. As I lay in the tiny, bare room, crying and clutching a stuffed lion that Mom had given me, I worried what people would think... Sure, I've written songs about partying, but my dirty little secret is that I'm actually incredibly responsible.''

Kesha revealed her self-image problems started when she went to middle school in Nashville, Tennessee, and while she managed to keep her demons at bay by focusing on her music and not her looks, she was unable to shake her fears of being an ''outcast'' and not conforming to the norm.

She explained: ''Ever since I can remember, I got bullied at school because I was different. Normal girls in the normal neighbourhood where we lived were supposed to be pretty and quiet and look perfect ...

''To cope, I dedicated myself to my music, working on it every day until, when I was 18 in 2005, I was signed by a record label. Suddenly, it was OK to be different. I had fun with my style. I wore my hair in a Mohawk and did my make-up like Alice Cooper.

''If someone called me pretty, I'd sneer and smear more glitter on my face. I didn't want to be just pretty - I was wild, crazy and free.

''I talked about sex, about drinking. When men do that, its rock and roll, but when I did it, people assumed I was a train wreck. I played confident but still felt like an outcast.''