Most relationships when you consider it are tiny tribes of two with the common issues being from loyalty, hierarchy, where they fit, and how they do things. Thing is most do not take the time to define what they want out of it. When that’s done you both have a common cause to work towards, which may help turn vicious arguments into calm discussions by bringing the focus back to that.
When you have a goal decided it helps bring you together. However, you still come from two different clans with their own hierarchies, routines, and rules. How these meld together is second to the first issue; to who are you loyal? Mostly an issue in a marriage, as you have created a separate new tribe that requires negotiations from equal partners. No one from the respective families come in to set the rules, traditions, etc. It can even be viewed as disrespectful to the other, causing insecurity (a main monkey brain problem).
Thing is to approach it logically, remember though to tell them how you feel without triggering their limbic system so much that the reasoning part is shut down. When you speak before you think, that is the limbic system. When it is triggered then through a force of will, you can change the role you are in from angry spouse to a disappointed one for example. At least to control your anger before you have another fruitless argument.
Tell them how you feel, get away from the topic for a while (a mental step back), if possible retrace the steps of a memorable date so you remember why you are together. Now that you are calmer you can discuss it like rational adults. Not trying to ‘prove who’s right’ but fixing the issue by explaining how you see things (without being accusatory) and asking how to fix it. Now you have a dialogue, preferably at a quiet spot in the beginning, from that you can rebuild the relationship.
It takes patience and commitment, all relationships have difficulties, and it is when someone is not committed to it that is where the death spiral begins. I hate seeing them fall apart with my own history of broken homes and dysfunctional relationships.