Advice please!

Okay so my boyfriend and I are in a long distance relationship. We’ve been dating for 9 months and I visit him every month. Lately, we been arguing literally everyday. We only argue because he gets upset of anything that upsets him and I try not to upset him but I always end up doing it. I would never make him upset on purpose, I want him happy all the time. We love each other so much but we just argue all the time. I asked him before if he had anger issues and said that he doesn’t think so but I think he does. I just want advice on what we should do because we love each other a lot and I don’t want to continue to argue every single day.