I think My Girl's Gone Crazy?

My girlfriend and I have been going out for about 8 months now and at first things seemed pretty good. We met at KFC (we met when i started working there). She had been working there for almost a year at that point. All the sudden, she caught wind that I thought she was cute, then i caught wind that she thought the same thing. I was involved with another girl at the time but we were not dating. She apparently was just using me... Anyway so eventually we started dating and I had started thinking that she was my perfect match. As soon as we got to know eachother to a personal standpoint, she started showing all the real emotions. At the surface, she seems really nice, hard working, and respectable. Underneath, she is a very angry person. My point is, she takes her anger out on me about every single little thing that sets her off (which includes the littlest things). She said she doesn't realize it when she's doing it. That's the main thing. She has PTSD (post traumatic stress disorder) which means that everything that happened in her past catches up with her and then she goes OFF. I am 17 and she is 20. She has a 4 yr old son. She pays no attention to me while she or I is home (which is almost never because she works all the time) I quit KFC a long time ago though so i know it wasn't because of us being co workers. There is a list that could go on forever about things that are just unacceptable and you would just need to be there.... We live together in the same roof but things seem to never straighten out. What do i do? Leave or what?