It's OK to feel angry. It's OK to express it in ways that don't hurt others or yourself. Here are some suggestions for how to use your anger to solve problems, rather than to create new ones.
Feel it! Accept the fact that you're feeling angry. Don't try to deny or explain away that tightness in your gut, those hot tears in your eyes, or that rush of energy in your hands or arms. Do your best to stay focused on your body. Thinking" about being angry isn't the same as feeling your anger. Observing your anger and being with it, like a news reporter on a hot story, is more immediately useful. Accept that something strong is moving through you. Feel it without assuming that you should immediately "do" something to get rid of it in yourself or to make it known to somebody else. Learn about how your body actually feels under the influence of anger. Notice your breathing, your heart rate, your posture. How does your skin respond? How does this feeling state start to affect your thinking or your motor skills?
The longer you can keep yourself attentive to the physical domain without acting out your anger, the more you'll learn about yourself. Although the mind can and will keep you endlessly agitated if you feed it with rationalizations and explanations, or reruns of the event you've just endured, the body itself seeks equilibrium. Observe the body long enough and without a lot of mental intervention (easier said than done) and you'll notice a change in those reactions.