You have been given at least some great advice.
Separating yourself from a situation to calm down may be necessary.
But you can master your anger. You seem young -- a lot younger than I was when I finally decided it was my issue, and stopped blaming everyone and everything else for making me get angry.
Anger is a choice. You can choose to no longer be angry, and you can eventually choose not to get angry in the first place.
It is not easy.
As I am neither a licensed therapist, nor am I offering you any personal counseling, I will not make specific recommendations. But what it boils down to is a handful of things:
Mindfulness. Be aware of yourself, in every aspect. Examine and study yourself. What happens when you are becoming angry? What physical and emotional responses are experienced when you start feeling the anger?
Those are signs which you have been bypassing without much thought. They need to become signs to change course.
And that leads in part to a widely spread maxim among those who practice magic, whether they incorporate a spiritual side or not: Know thy self. The better you know yourself, the more easily you can change yourself for the better.
Some more aspects to controlling anger: Learn some mantras and breathing exercises. It sounds a bit white-light and fluffy-bunny, but they need to remain positive. Remove words like "not" or "no" from mantras. In stead of "I will not be angry," try, "I will remain calm."
Learn to observe your thoughts and emotions during meditation. Do not become involved with the thoughts; acknowledge them and let them pass. It's the same with emotions. Yes: That whatever event was exacerbating. Let it go; you're better off not escalating a situation.
I have pored over books and exercises. It has taken years, and I still have miles to go. Get on the right path now, before it is much more difficult to improve yourself.
Magic, remember, is change in accordance with will. What better place to start than internally?