For me, anger stems from fear and fear stems from one of two places. Fear that I am not going to get what I want or fear that I am going to lose something I have.
Fear is like a door. I can try to go around it, over it, under it; but the best way to get to the other side and freedom is to walk through it.
When I do that two things happen. One is that I usually find the fear is nowhere near the bogey man I had built up in my mind; and the second is that I discover I have way more strength of character than I give myself credit for.