Make yourself crazy?

Ok, this is probably a stupid question, and I realize it's probably NOT possible, but is it possible to make yourself go crazy by thinking about a really scary thought or something you can't figure out for too long. I know the phrase "I'm making myself crazy with this math problem" or whatever, but can you make yourself litterally insane? I had a good day yesterday and today until i had to go to work, that place is like poision for me. I got the thought that freaks me out almost more than anything, which is how am I thinking thoughts...and distraction is hard when I"m thinking these thoughts, because the thoughts themselves are problematic. It's like "how do i form thoughts, when I am forming them, where do they come from? How can i form them while thinking them." It's like I picture them coming from some well into my head, but i'm the one creating them. I dunno it's hard as crap to describe it, but it's really really freaky. Does anyone understand this? Is good old focusing outward the way to go, just distract myself from it? It's maddening sometimes. Sigh...first day of classes tomorrow, and the psychiatrist, so hope that will help. Thanks for listening to my rant.