The truth of the matter is that he broke your trust. This fact does not change. You also may have an anger problem, and this is a secondary issue. When we feel sad and insecure, we tend to feel angry as well. So, there are a couple of things to be resolved in this situation on my point of view.
To gain trust is not that easy but it is easy to lose trust. Try to talk to him, and understand why he did what he did. Try to search in your heart a place of forgiveness, because in the end nobody is perfect. If you do believe that he will not do it again, and that the relationship worth you time and emotional investment keep it. Try to think with objectivity, write the good and the bad points on a piece of paper.
Anger does not solve anything. It is uncontrolled and negative. It hurts you and does not solve anything. Try meditation, relaxation and control your breathing. Sadness and insecurity may cause anger. He did not cheat on you, he cheated on him, on a relationship. He would have done it with anyone. Love yourself before loving him. You will always have yourself to count on.
He does not help you, he makes you angry/sad and so on. Invest on you more than on him. Read some self-help books.