I need help PLEASE, dont know what to do.?

We were at a party a few weeks ago and we both ended up pretty drunk and ended up making sweet weekly love again. As far as we knew I used a condom but then she started getting sick the next week and we didnt really think about it. She wasn't on the pill due to a few complications about other medication. Last week after she wasnt getting any better we talked about it and we got a home pregnancy test and the first one was a false negative but just to make sure we tried it 3 more times and all three other times it came out positive. I'm 22 and my girlfriend is 18. I know I love her and we've been together for about 4 years but this is causing a rift between us. I am not financially able to support a child and she has been untalkative and very distant from the problem at hand. She has been blackmailing me with telling my parents and forcing me to pay for clothes and speacial treatments every day now. She even wont let me hang out with any of my friends. The other night I was on the phone with my boss who is a 63 year old woman about a problem at work and my girlfriend heard me (I was in the kitchen) and threw a fit. She took the phone and yelled at my boss cussing at her and calling her a "geriatric ". I tried to stop her and she shoved me against the counter and I fell on the floor and a plate fell on my face and knocked out two teeth and fractured another. Now I'm not only out of a job but I am scheduled for an oral surgeon which will cost me about 300 dollars with insurance to get it fixed. I dont know who to turn too. I cant leave her or she'll get her ex-military father to hurt me and tell my parents about the pregnancy. I dont plan on leaving her because I love her and I think it's just her hormones but I cant handle much more. She's hit me at least 5 times today and it's not like I'm going to hit her back. She's making me have with her at least twice a day and it's really uncomfortable for me knowing she's pregnant and the fact that she makes me let her urinate on my face every time we do it which is a very new thing to me. Before she was a loving caring person who wouldnt hurt anyone and now she's not only abusing me but she's making the kids she baby sits as a side job watch us have . The kids are a 5 year old girl and a 7 year old boy. The parents have no idea and her behavior gets worse. She's started drinking more and more and has started stealing pills from the family she babysits and I'm afraid she's harming not only herself but our unborn child. I really need advice. Please serious answers only I'm dead serious about this and I dont appreciate being called a "troll".