I assume that you are already trying on your own to control this and it's not working. Get some anger management counseling, at least enough to learn the various techniques of recognizing when a "flare up" is coming and how to "put the brakes on before the actual crash."
A good way to relieve anger is to spend time by yourself. You can go biking, draw in a notebook, go running/jogging, and more. In my opinion, the best way to relieve anger or stress is to write down your feelings in a journal.