When you feel such anger, close your eyes or think about something else and start counting 100 in backwards.
I agree with above comments. But don't just try deep breathing when you're angry. Start deep breathing and meditation everyday in the morning. Make it a routine. Now whenever you get angry, take deep breaths, have a glass of water, and count no.s backwards. That way, your mind will divert from the topic at hand and by the time you finish counting, your anger will have vanished. However if you still feel the need to vent, try a calmer approach