I am in a similar situation I have always been the type to confront rather than just walk away from a situation. I do not initiate any, but I find it hard to suffer fools. Most of my issues are caused by Prednisolone which has worsened my tendency to react badly, as well as personal traits. I have found that adopted what I call the "ah well" mentality so that when encountered by something that in the past would cause an issue leading to confrontation, I just say to myself "Ah well". I started taking medicinal cannabis CBD in the morning to allow me to drive and THC of an evening when I no longer need to drive. I have slowly gotten better but have accepted it is just a part of my makeup, and I have to deal with it. If I slip up, I do not allow it to ruin my progress. And in some cases, it is unavoidable. As to why I am like this, I don't know according to my mother I have been like this since I was a young boy. I know as I got older things improved but life has not been an easy ride for me e.g. lost my first wife to cancer with three young children 4 and under. Had a lung transplant after coming within days of dying and the medication needed causing adverse effects. I am no Psychiatrist so I cannot give a definitive reason.