You ran into an a\*\*hole. They aren't worth your consideration. Other than their tantrum, did anything else change? Did your manager replace you? No. These sorts of things are what I refer to as "wrong think." You're allowing bad thoughts to propagate. You didn't do anything wrong. You couldn't have done anything different. There's no blame or shame for you to carry. One of the things I used to do was relive events over and over in my head. "If I would have responded this way..." "Maybe I should have..." It's all BS, and serves no purpose, other than to berate and belittle yourself. Those types of thoughts are usually much to specific to the incident, and in no way prepare you for any future incidents. Tell yourself to "stop" when you find yourself wasting time on wrong thinking. It's not easy. It takes practice. But you can start to learn to stop dwelling on other people and things outside of your control.