The 43-year-old musician, however, says he has tried to look at the brighter side of things to get by, reports FemaleFirst.
"This job is really bad for my health. It's going to kill me. Unless, I view it in a different way," Williams tells The Times.
The "Feel" singer wonders if he would be as mentally unstable had he not been in showbiz.
"It sprints through my family. I don't know if I'd be this mentally ill without fame. I don't think it would be as gross or as powerful if it hadn't have been for fame.