I have experienced alot of what you described but from the opposite side, I am autistic and i think that has alot to do with why such small things set me off, not saying she is but might be something to consider.

What helped me was simply sitting down and working out what sets me off and working to avoid it. In regards to going off on one at my bf, lots of discussions when we are both calm and huge effort on my part to remember and recognise that he was simply doing what we discussed and waiting until i was calm to talk to him afterwards. It took time and he was/is a saint for putting up with it. It didnt change after one conversation it was repeated discussion and positive reinforcement for myself when i did better over a long period of time that fixed/is fixing it.