Second guesses.

I've been in a sour mood for the past couple of days and I can't figure out why. I find myself second guessing myself a lot lately, and I hardly ever do that. I don't know if it's because my job, or if its all these late nights but its getting to the point where I'm starting to annoy myself. Do people find me as annoying as I find myself sometimes? I hate feeling like that, I want to know whats going on in my head, but I can't find the right door to open. I guess everybody goes into this moods from time to time, but I want to be over it and find my old self again.