It's important to remember that, no matter what you were told growing up or whatever someone might be trying to convince you now, fighting is not a normal part of any relationship.
Differences in opinions are normal. Bad days are normal. Moments where you're irritated and tired and want space are normal. Having to sit down and talk something out is normal.
Shouting matches, insults, threats, arguments that last for hours, passive agression, purposely trying to hurt one another, these things are NOT normal or healthy.
This goes for every relationship. Family, romance, friends, peers, there is no kind of relationship where trying to tear the other person apart is okay.
Abusers will swear to you that it's impossible to have a relationship without blowing up at each other on the regular.