go and sleep, you will feel better later.
Sometimes i'm in this weird mood and I will feel sad all the sudden. ( I had a lot of pressure at work sometimes) But then when I change how I think, I get less upset. Instead of thinking "Oh, I'm the same old me... ", why not trying to change the question to: "what can I do to improve myself? How do I make sure I will remember to do the laundry?"Oh, let's say, "I ate a chocolate, what is nice about it? Yum... tasty chocolate..hehe..okay no chocolate for the next 3 days" =)
Cheer up, a soul like yours deserve to be happy =)