Wow, in a way I'm glad you posted this. I've had days where I feel the exact same and I don't know why I'm mad - just that I want to scream and throw a tantrum until I'm exhausted (not that I do haha) and they usually end up in me isolating myself until the emotion passes, and then I feel sad because I hate that I get these moods and that they impair my ability to connect with other people.