Well, you aren't married. End the relationship. It's stressing you out. You can just say it, you get into fights every 3 days and you don't want that.
Of course, my suspicion is that if she is instigating the fights, then it is a pre-planed way to get you to give up on the relationship.
Step 1: give you a hard time over anything. Even if there is noting to argue about, reframe the situation to make it arguable.
Step 2: repeat until you give up.
Why? To get out of the relationship without looking like the "bad person" or because there's a third element: friend, sister, another dude, cousin, or someone else, who has enough control over her to "puppet master" his or her way into your girlfriend's mind to get her to want to end the relationship.