I used to cry a lot for a lot of reasons. I went to therapy for years and cried there too even though I didn't know why. I have done other things to improve my mental health and now understand that I was very angry. I can't say why I was angry or what I was mad about but all that emotion stored inside me was one of the reasons I cried. I was also depressed which made me cry.

The things you and your BF argue about are not big issues and seem to be the usual causes of diagreement for couples. You may be crying for some unrelated reason. Therapy may help you figure it out. It is worth at try.