just broke up with my girlfriend and i feel awful

Hi,

We'd been together just over a year. Her last relationship was abusive, she has suffered enormously before that too. Her parents aren't there for her and she doesn't have any real friends to speak to apart from me. She doesn't have a formal diagnosis but we've both spoke in the past and definitely feel she has BPD and depression. I've tried to help her see someone, but she was reluctant, although she finally had a doctors appointment in a weeks time for low mood and was likely to be prescribed anti-depressants.

Onto us, it started great, has gone downhill quick. She displays all the signs of BPD, the anger, violence episodes where I go from being the best in the world to the worst. I've tried to take it all but i can't. I love her but there are only so many times you can hear that you are disgusting and that she wished she never met you. I understand she is in more pain than me, and i haven't helped at times and i do snap back when she is at her worst which i know i shouldn't. She has got more aggressive too over time, even pushed me hard the other week. She self harms, talks about suicide and then blames me for it.

The last two weeks were the worst, everyday constant arguments where i would end up hurt and she would be in a really bad state. She always said i made things worse, so i asked her to leave and she did yesterday. Today I told her I can't be with her anymore, that i'm not good for her problems and can't handle it.

I now feel so selfish and guilty. My self-esteem is in pieces, i was on eggshells all the time and constantly accused or told how i didn't care. Despite my unhappiness I love her and wanted her to be happy, her problems are so much worse than mine. I didn't want to end it, but it's making us both unhappy so i felt i had too.

She will be alone at home now, with no one to speak too, in the worst place because of me. I feel like the worst person in the world and I just don't know what to do. I don't know if i'm just venting, or if I want advice or just someone to say that i've done the right thing... have I? i've lost sight of whether i'm a good person or not...

Thank you to anyone who has read this far and i'm sorry for any spelling/formatting errors.