How to deal with anger

Lately, I noticed that I have a lot of anger in me.  I react very aggressively in many situations.  And I am always sure to be right.  I mean for me, the people acted in an inappropriate way which made me explode!  The problem is, I don’t want to have those kind of reactions.  I want to be able to explain that I’m not OK without being mean, aggressive and very very rude.
I tried to put that in a model, but I didn’t succeed because it’s like I don’t even think… I don’t have the time to notice my first thought.
For example:

C: My friend asked me why I changed my mind
T: whaaat????
A: Yelling at her because it’s none of her business
R: She and I were upset

C: The waiter didn’t change the order even when I asked him
T: I Can’t accept that
F: Anger
A: shouting at him
R: He changed the order but too late, my mood was bad and I didn’t appreciate the rest of the lunch

Thanks for your answer.