Couples fighting is very common, so common that you will be surprised even the very best of couples fight everyday. I usually tell my partner, fighting isn’t the issue, disagreement isn’t even an issue, it’s a normal occurrence in any great relationship. What matters most is whether or not the reason for the disagreement and fight is understood and settled and this is not something easy to do. I have understood that I can never understand my partner 100%, this is why I do not try to avoid some kind of hard discussions because every relationship is a learning phase, and that phase will continue until forever.
There was a time I had a fight with my partner that lasted almost two weeks, at the end of the day I realized we were fighting not because of what was happening but because of how we felt about what was happening. For example, she felt abandoned and I felt disrespected. When I realized this I apologized for making her feel abandoned and she apologized for making me feel disrespected. Then we decided that to always communicate how we feel about something because it will better make us understand the reason the other person is not happy. Since then our fights do not last more than a few hours. The only other time it did was when our pride got in the way that made us not talk to each other for almost an entire day.
Good thing we realized, communicated our feelings, understood each other's perspective and made amends. It’s one thing for my partner to be angry and tell me she doesn’t like how I am always scattered, but then I might not take it as seriously as when she tells me how my being scattered makes her feel. If she tells me that my being scattered makes her feel irresponsible It will definitely change how I react to it because I wouldn’t want her to feel irresponsible because of me. This is how we try to communicate our feelings instead of communicating just the problem.