It happens to me when I feel like even after hours and hours of arguing the person in front of me doesn't understand or is not even trying to understand what I'm trying to get across. Also if they ridicule me, insult me and don't let me talk it becomes another form of 'fuck it' which is pure despair. I can stand it for a while and try to make my points or explain myself with little spirit but I have a breaking point which can turn me into one of two things: Either I lose touch with reality and shut myself in somewhere trying to run from everything or I start yelling and throwing things around and spitting out insults myself. I am yet to find a solution to prevent this from happening. Thr best solution is a peaceful, respectful, safe environment.