How do I manage to cope when I am really angry?

Play sports, remember a good thing and drink cold water, have some candies or get meditation and reflexion

The immediate response is I start to drink water, even if it is 4-5 sips I will take it. While drinking I focus on the sensation where all water is flowing through. It not only distracts me instantly but also kind of calms my nerves. It also gives me time to understand the situation and helps me think all perspectives rather than just reacting in random fashion. If this does not work I tap my feet in a way of exercise or dance because I feel it removes or stabilizes all the unstable energy within me. Generally I respond to any such situation only after I feel I have a well justifiable response.

When you feel very angry, I suggest you try to stop angry thoughts and count backwards from 10 to 1 in your mind. This can help you ground yourself and not act impulsively when you are experiencing anger :) and if the issue is such that you are unable to express anger but feel very uncomfortable due to with holding it, then you can write out your angry thoughts on a piece of paper and let it out of your system and right after writing such thoughts (in case triggering ) you can simply indulge in an activity that you like to do, just to let your mind transition away from what you write and vent in the paper.