I know I’m a victim of abuse, but I can’t bring myself to leave.

I don’t even know why I’m posting this or what I’m trying to gain from it. I just feel so defeated. I (30 F) have been with my partner (32 F) for a year now. We celebrated our anniversary recently. Anyway, since day one of the relationship there has been hardship. She used to have an issue with drinking and being very aggressive and argumentative with me. The main issue in the relationship though is trust. She has never trusted me and never given me any reason to trust her. When she has these ‘episodes’ she is so unbelievably hurtful to me every single time. And each time she is worse. She has called me names, harassed me, contacted my friends to say bad things about me, threatened to cheat on me, I would just like to make a point of saying that I have never and would never cross any boundaries like that in this or any relationship that I have committed to. After every fight she either has me believe that it’s my fault and I beg her to come back, or she says all the right things to win me back and make me believe there is going to be a change. She is so jealous and controlling and I’ve had to cut people out of my life, I feel so isolated, I have lost a lot of weight, people have noticed and often comment on it, my hair was falling out, I’m not sleeping. My therapist told me that I am a victim of abuse, but it knowing that doesn’t make it any easier to leave. in an argument recently she came after me for my recent mental health issues amongst other things outside of my control which hurt me very much and I haven’t seen her since although have texted infrequently. 
I feel heartbroken that my relationship has been destroyed over something that hasn’t happened, it hurts me so much that the woman I love can be so cruel to me and I have met myself down by allowing and continuing the relationship.