It's very difficult to deal with anger once it's up and running, like trying to stop a boulder that's rolling downhill or trying to change the direction of a ball you've already thrown.
What we need is prevention: to look carefully at how and when our anger arises and learn to develop a longer fuse. We know that it is possible, because when we think about an angry episode a week later, our perspective has already changed and we can see how we could have acted more appropriately.
Prevention requires being very methodical at first. Sit in a room and imagine different scenarios in which you lose your temper. . . . Then, when you find yourself in actual situations that make you angry, your anger won't last as long. As you become aware of how you respond to negative situations, you will learn to pull back from confrontation. Instead of exploding, saying and doing things that you will regret for years, you will be able to pause before you react. You will say, "Aha! Here it is. This is my anger; this is what I've been working with all this time in the privacy of my bedroom." In that short interval, you can choose to respond differently.
— Chagdud Tulku in Change of Heart by Chagdud Tulku, Lama Shenpen Drolma