I'm so over it :(

My girlfriend has hurt me a lot in the past 4 years from cheating and lying ... even lately she lies about gojng out clubbing and didn't msg me for 16 hours but told me she just went for dinner. I found out by someone telling me they saw her out and she still denied it till she finally told the truth.
Anyways - my point. I have had a really low sex drive for a few years and I can't help it .. I just have a big wall up.. 
Tonight she started a fight with me cause the last time we had sex was a week ago, and started saying all these horrible things to me .. telling me I need to get over it ... and I actually can't help the way my body is ..
So I left crying and went to the couch! By the way it's my house!!! After she screamed in my face I got up and balled my eyes out on the couch.. I have been laying here for 40 minutes now and she hasn't even come out she's asleep...... 
:( she really doesn't give a fuck