Does my girlfriend enjoy seeing me upset?

I love my girlfriend dearly, but she is driving me crazy. She picks up fights at the slightest opportunity, no matter how flimsy the reason is. 

And when she gets upset, she stays agitated for hours or even days. I hate the tension this brings into our relationship, so I always attempt to end the fights, but she rebuffs my effort every time. I wonder whether she enjoys fighting or seeing me upset.

Of all four intimate relationships I have been involved in, this is the one where I've experienced the most passion, but also had the most intense and drawn-out fights.

I can't take this any longer, yet I do not want to end the relationship. This is the girl I want to marry.

How do I tell her without her getting upset? How can I help her control her temper so we can have a blissful relationship?

Distressed