I think my mother emotionally abuses me and my dad. Is she? How do I cope?

For as long as I can remember she has been the speaker of mean, close-minded, snide comments. I'm 20 and since I was a kid I've heard her say all kinds of stuff to my dad, called him an abuser, said he was worse than his mum who's passed, told me I'm not what she wanted, that she doesn't like me, kept secrets. These are slight specifics but basically she is callous and attacking but then has moments of being lovely. It's hard to handle and is confusing.

I know that before they got married mum had problems with dad but he's always been an amazing parent to me and has kept 95% of their many many many arguments away from me completely. In my opinion, if she had issues with him she shouldn't have said yes when he proposed.

Dad's resigned himself to just not replying to save the argument. Last year they told me they were divorcing then changed their minds. Dad suggested that he moved out while they went to therapy to try to fix things but I insisted that he stay because I didn't want to be left with her. He stayed and now I feel guilty that I've moved away to uni and he's left to deal with her.

I literally broke down and had a borderline panic attack trying to tell her how she upsets me last night and she played victim as always and refused to accept that she made me that but insisted I was doing it to myself. She wouldn't listen, she never does so things never change.

This has turned into a bit of a rant but I need advice on how to cope, because it's getting so difficult.