My advice is: No matter what you are confronted with, try to find something to laugh about first -- before any other response, reasoned or emotional, seek out the humor. You don't have to let other people know that you are doing it, but do it for yourself. It's gotten me through everything.
I think this is why I like Larry David, and by extension, Curb Your Enthusiasm, so much. There's a guy who no matter how angry he gets, he just starts laughing the whole way. It's a riot to watch, but I imagine it's an even better way to deal with anger and frustration than just raging.