"I liked Reality better when it was a Dream"

I think too much. The more I think about things, the more fanatical I get with the scenarios and situations I make up in my head. It's ridiculous. I have absolutely no grounds for thinking these things. No evidence, no cause, no rationale or reason. It's stupid. It makes me worry. It makes me sick. It turns me into what I am right now, the past couple days. I don't like it and I want it gone. AAAHHH!!!!