Why wont my mom understand that I have anger issues?

I understand you dilemma I am guessing your in your teams, high school maybe at those were the worst years. I will give you a few answers; first, this is something most of us go through at that age and it is difficult to believe that anyone else was ever there, especially our moms. Second, if you think you are over reacting you need to search for an outlet (running, yoga, reading, art, calm breathing). Find what really calms you down the most, there is no one calming technique, it is whatever works for you. Trust me the anger will still be there when you get older, I often wonder how those people older than me stay calm, we just handle it differently with age. Third, this just an idea and you don't need to change your religion but look up information on buddhism/meditation the relaxation techniques are useful for anger. And last try to stay away from things that hit your anger like certain movies or books, I had no idea how much some movie bothered me until I stopped watching them as much. Your friend is included in the above sentence, if she/ he hurts you, either confront them with one more chance or look for better. Real friends don't use you and you deserve better.