(SCREAMS!)

Ok, I need a freakin vacation! Heres whats going on. My mom was letting my cousin stay with her, since her stepdad wouldn't allow her to live with him and her mom. My cousin is 22 years old, and likes to party, get really drunk, and bring random guys home. My mom is not ok with that, and she let her know before she moved in, that she cant do that at her house. At first it was working out ok, even though she was drinking a lot. Well it kept on getting worse, she had tons of random guys she met at bars over, and eventually my mom talked to her mom and told that they didn't agree on this, and it wasn't ok with her. So my cousin got mad and said that she is an adult and should be able to do what she wants. (But she is living in my mothers home!) It kept getting worse, she was making big messes, and she would not clean up after herself, she still brought random guys home, my mom has been woken up many times in the middle of the night by my cousins friends, because my cousin was too drunk to walk, and my mom had to come help carry my cousin inside. My mom talked to my aunt again about it, and she said something to my cousin, so my cousin got mad, and said that she wanted to move out and have her own place. Well she barely works, so she cant afford her own place, and she wanted her moms husband to pay for an apartment for her. They agreed that if she passed all of her classes this semester that they would get her an apartment. Well she constantly tells me that she hates living with my mom (And my mother is one of my best friends!) and talks bad about my mom to me, which makes me really uncomfortable. Last week, she was telling me the house was going to turn into a war zone, and talking more crap. Then she started talking about my moms best friend (Who is like an aunt to me) and I told her I didn't want to be involved with anything. That I loved both of them, and I told her that my mom felt uncomfortable with her there now too, so maybe she should find somewhere else to live. I told my mom what she had said, so my mom had a heads up before coming home to a "War Zone", and my mom called my aunt about it. Well she called my cousin, and my cousin called me and text me calling me a B*tch, saying that I'm a bad sister (We call each other sisters cause we were close, and were both not with our siblings). Talking a bunch of Sh*t to me. And this was while I was in the hospital twice last week for the baby. Then Sunday night, my mom got woken up at 2am by my cousins friend, because my cousin was sleeping in the middle of the street by the gate (my mom lives in a gated community), and she would not get up to walk home since she was too drunk. So my mom went and helped carry my cousin inside and put her in bed. The next day she sent an email to my aunt letting her know what happened, and told her that my cousin really needed rehab. My aunt didn't say anything cause she is mad that my mom wants my cousin to move out. Well we hadn't heard anything yesterday, but I just took my puppy out to go potty. I see my aunt walking through the parking lot (I live in an apartment). I was like what is going on?? Then I see my cousin walking toward my apartment. Turns out she rented the apartment right NEXT DOOR to me! There are 600 apartments where I live, and she chose the one right next door to me?? I dont know what I can do, I dont want her living there since she parties and stays up late drinking with people over, and I'm going to have a newborn at home. I left a message for someone at the office, because I honestly think if she is going to be staying there, me and DH will have to move. Now I'm uncomfortable going outside my own home!
I'm sorry for such a long rant, but now I'm not sure what I should do. We still are under our lease agreement until October 1, so it would cost us quite a bit to move, but I feel very uncomfortable being here. What should I do?? Thanks to anyone who had the patience to read through this, I appreciate it very much.