Your post is very moving. There is no test or rehearsal for parenting and family interaction and so many get it so horribly wrong. Having said that, once we are old enough we all have the choice and ability to distinguish between acts of good and that other thing...as Sannah said you don't owe your mother anything; just you - and your own happiness and healing I wish you all the very best in that.
...
I think I can empathize with a lot of what you wrote there. I hope they will leave you alone soon. Good friends with non-judgemental ear work wonders. I have a dear friend and mentor who once just let me howl on her sofa for almost a whole day while she brought me cups of tea. Just to have been given that space was such healing for me.
...
I have been cajoled, bullied, "sent to Coventry" and punished with hate-mail by family because I finally found the strength in my early 30s to stand up for myself and move away from my very sad and sick family. Well a little over 10 years later I still do not speak to most of them and they are happy for me to be the scapegoat and move away with the family sins on my back. I live overseas and everyone is suddenly disturbed by the rumour that I want to move back to England. I even got a nosy call from my father yesterday who, although he didn't have the courage to say what he'd heard, told me point blank not to return! It was my birthday and he just quoted revelations all evening - made me sad and a bit scared actually.

To all survivours - in the face of adversity and manipulation - give 'em hell!