Do not, I repeat, do not look her in the eyes.
Yeah, so your girlfriend sucks. Anyone who needlessly argues is a blatant parader of deep insecurity, and I’m guessing she’s not any more ready for a mutually beneficial adult relationship than she is to swim with river piranhas.
Of course, fighting is always bad thing; it can be immensely beneficial to air out your issues and communicate your vulnerable sides. In fact, for some couples, fighting can help them reach resolutions faster and both people get over the issue quicker. But “liking to argue” is another thing. Needlessly creating drama and discord is an entirely different thing from caring about an issue or a person enough to raise your voice and send your grandma's porcelain urn sailing across the room to make a point. That’s a cry for dominance coming for someone who feels like they have no control.
The only way to deal with that reaction is to realize the root of their discontent and empathize with it. When you can do that, you stop seeing their lashing out as an attack on you; rather, it’s their way of saying they need to work something personal out. People who fight needlessly often grew up in homes where fighting was common, or had relationships early on in which they fought so much it seemed normal. So, when you’re dealing with someone like that, know this: You can’t reciprocate the drama because they’ve never had an experience where fighting wasn’t part of the picture. You have to be the person that changes that if you really want to be with this person.
On your end, you have to approach fighting differently if you want it to stop. Next time she starts something with you, don’t give in to the drama. Listen to what she has to say, take a sec to formulate an articulate response, and then reply calmly and logically. The more you can empathize with her and try to see thing from her point of view, the quicker she’ll calm down because she’ll feel validated and understood. One of the quickest ways to get someone to calm down is tell them you can see their point. Assess the problem through their eyes, and dictate what you see. If she’s pissed that you’re hanging out with your female co-worker a lot, say something like, “I can understand why you think I’m interested in her. She’s another female that I’m giving attention to, and that must feel uncomfortable for you. You must feel not good enough, but that’s not the case. If I were in your place, I’d think the same thing, but she only blows me twice or twelve times a week.”
Occasionally, this might mean you compromise on asserting yourself or your side of the story and that you let her "win," but you have to pick those battles. Is it worth getting her to see your point all the time when you know she's probably frustrated about something else and just taking it out on you? If you really care about her, just know that her fighting with you is more than likely her projecting an internal issue on to you, and you need to be receptive to figuring out what that is if you want me to stop calling the po-po on you because you’re loud as fuck and I’m trying to watch this ‘70s porn in peace.