A physical release is what you need. Boxing or some similar sport would be good but swimming or running is an alternative if the anger is not so much.
Otherwise, diazepam or something from the doc can do wonders to relax you. Kind of a magic pill that sorts out lots of issues but the GP's don't like giving them out as some people can get addicted to them. Instead they will probably suggest 'mindfulness' and breathing exercises...
Lastly, sometimes it just feels great to actually smack the guy who deserves it and the satisfaction and action takes all the stress out of your system. Did I just say that out loud?