London, Oct 12 English singer and X Factor judge Cheryl Cole has revealed that she is suffering from stress and sleepless nights as she is worried about her wannabes.

The Girls Aloud member has formed a very close bond with the girls Laura White, 21, Alexandra Burke, 20, and Diana Vickers, 17, and at times the judge finds it very difficult to separate her role of mentor and friend.

Besides doing her best for the girls, Cole is also trying hard to impress series chief Simon Cowell, and she also has to work hard in promoting her band the 'Girls Aloud'. With all the running around she has to do, Cole, 25 also admitted that the pressure is taking its toll. "I do feel under so much pressure to do well and win," the Daily Star quoted her as saying.

"But it's not about myself doing well - I just don't want to let my contestants down.

"I want to make sure I do my best for them, not me," she added. (ANI)