Anger Management Support Group
Anger management commonly refers to therapeutic techniques by which someone with excessive or uncontrollable anger can control or reduce their emotions. Typical examples include the use of deep breathing and meditation as a means to relaxation. Psychologists recommend a balanced approach, which both controls the emotion and allows it to express itself in a healthy way.
It's good that you don't back down for things that you stand for, but maybe try to be less aggressive with it and more assertive. You can be assertive in what you believe without being aggressive! You might come across the wrong way if you say things in a certain tone.
With situation like with that credit card guy, try to remember that he works there but he didn't necessarily do anything to personally fuck with you lol. That's like when I'm waiting on a table and a customer flips shit on me because we ran out of mac and cheese. They act like it's my fault that we ran out, but really I had nothing to do with it lol. Maybe try to see it from the other perspective.