Help!!

I think I’m in a abusive relationship. My girl friend ( I’m bi ) have been together for 5 months and the first month was perfect. But after that she started getting very aggressive towards me and recently has been pinning me down screaming at me for nothing at all. Last night she drank a lot and repetitively hit me and would get so mad at me to the point where she would be screaming at me in front of 15 people and just telling me to go home ( but she was my ride ). I have tried to leave many times but she has told me she would change and she did until she started getting angry again. What do I do? I love her so much and I don’t wanna hurt her by breaking up with her. We have good times a lot but the bad times are so bad it makes me afraid of her. Please help