Do you have anything in your life that particularly bothers you that you feel unable to control? Anxiety or depression are the big two things I'm thinking of. I found when I had depression I had similar problems controlling my anger, I'd often get nosebleeds I got so angry. But since I've recovered from depression I find that things bother me a hell of a lot less. I can't even remember the last time I got angry. I dunno, might be worth looking into?