I think I'm crazy
Why would you think you are going crazy?
I can't stop banging my head against the wall.
I think it's worth getting checked out by professionals. The more you think like that and the more you continue with this behavior, it will turn into a habit.
I'm not crazy and don't you know I'm talking to myself while writing this chat with you.
That is a serious problem. I am a real person, and I think you should seek psychiatric care right away.