Mom/Girlfriend Conflict?

I have a major problem. My mom got in an argument with my girlfriend of 2 years and I about how my mom basically hates my girlfriend. I do not have the financial stability to move out of my parent's house and I am currently a full time student with a part time job. I feel like the only way to make the situation better is to move out of the house. The relationship between my mom and I has changed significantly, I try to not talk to her as much about anything because I feel like she will use anything I tell her as ammunition in our next argument. The argument between my girlfriend and my mom was about 2 months ago and my girlfriend has not been over my house since then. My mom will come and pick fights with me every now and then talking about all sorts of things that don't make sense. Most arguments have no structure and have no focal point, it is essentially her coming to room and verbally attacking me. Then in response to this attack, I will attempt to resolve any issues and she chooses a new attack plan so she can continue arguing with me. I just don't know what to do anymore and I need a third party opinion. Please Help!!!