I'm also short-tempered and bitchy. Well, okay, I'm bitchy all the time, but not usually short-tempered!
Curiously, while this is all happening on one side, I have a couple of really excellent, happy-making things on the other side, which continues to be confusing. So maybe I'm not depressed at all, and, instead, am simply lazy. In either case, the treatment is clear: get stuff done. This will make me stop feeling shitty about being lame.