SUBREDDIT: r/relationships
TITLE: Me [21 M] with my girlfriend [23 F] of 5 months, we just don't work. Help?
POST: So, there's this girl I started seeing in the Summertime, after I broke up with a woman who basically tried to secretly get pregnant by sneaking  my swimmers from the condom we'd use (different story, I can talk about it if anyone's bored). 

I thought that this new girl seemed interesting, she's beautiful, and she had this energy I liked that really attracted me to her. Fast forward a bit into the future, and I've lost the passion I had for her. She self-inflicts pain to herself to stop being stressed or angry, she seems like she's never happy anymore, she gets upset at me for things that she doesn't even talk about to me. She just gets angry and makes me suffer without knowing what I did. As soon as she tells me what she's upset about, it's usually something that gets solved as soon as she makes the issue clear to me. She basically views the relationship as "who is winning" in visits to each other's houses. She's anti-social, but I'm a social butterfly. I don't know if I really do care as much as I should at this point, I actually feel stress when I talk to her. So, do I stay with her, even with our differences, or if I break up with her, how do I handle it? 

I'm at your mercy, Reddit.
TL;DR: 
Thought she was a positive, out-going girl, but is the complete opposite and is in love with me, but I don't love her.