Leave your job, look for a job that you like.

take your keyboard slam it against your screen, say sorry to your boss, then you resign or your probably gona be fired...

I know it sounds cheesy but try to walk away or close your eyes concenrtate, count to 10, this will put things in perspective for you and you will realise what you really want from the situation aka to keep your job

First you need to know what makes you angry at work. If its one or two situations then you can fix this by talking to your superior, its no big deal. If everything makes you angry, then sit alone with a mug of coffee and think. It could be a problem within you. I feel angry on every situation when I'm hungry irrespective of the size of the issue. Make sure you have had your meal bellyful, because when we are hungry we have no control on our anger. Every issue has a solution to it. When we lose control on anger we not only raise the gravity of the problem but also lose time that could be utilised in solving the problem and eventually end up making things worse.