Have you tried reading anything? That used to help me. I think you'd appreciate works of Dostoevsky (if you like big novels) or Camus (if you're more into novelettes) or Kafka (he has some amazing short stories) more than most people. Dostoevsky is a good read if you want to do some self-evaluation or just to understand the human psyche a bit more; I'd recommend The Idiot for someone in our case, but overall Crime and Punishment is better. Camus speaks to the heart of what you talk about; you can read things like The Stranger to get a feel of what he believes, but you can also just read his essays (they've really changed the way I view my fatalism). Honestly, I'm not that much into Kafka or the rest of the existentialist writers, but I've done some short reading and they can be pretty relevant.
Of course, if you don't like reading just ignore everything I just said. Reading was therapeutic for me, but doesn't mean it is for everybody. If nothing else, I'd strongly advise you to read The Myth of Sisyphus by Camus.
Other than what I've said, all I can say to help you is that I know how you feel, I've been there, I'm there now. Just yesterday I totally screwed myself over, and I feel more freakish than ever.