Well - this seems to be more then just some anger issues. This sounds a bit like there are some borderline mental issues. It is good that he is not violent and can accept his issues inside a relative short timeframe.

It sounds though that you need to take a sharp look at yourself. You need to define what kind of behavior you should display when dealing with him.

Right now - you seems to go all the wrong ways. Why are you apologizing when he is in the wrong? He has to deal with that. Why are you trying to interfere, when he is in a fragile mental state - and taking the risk that he will become angry again? Why are you giving him gifts when he is showing anger issues - it is like you are trying to reward him? Why to you not train yourself to recognize he is starting these "microaggressions" - that clearly come before his main attack.?

These are things you need to think through - and maybe sit with him and your therapist and discuss.