Hello there
Am sorry that you've such a person for a mother.. Sounds like you're one of the unlucky ones. Not everyone should be a parent, and when a mum isn't what she should be it's probably one of the hardest things to accept.

And accept is what you've got to do am afraid. Accept that she's not well herself (being evil, cruel and mean to a daughter isn't what I call normal), accept that she probably will never change and you cannot change her, but the biggest thing of all, you need to accept that none of this is your fault.

I am a firm believer of being responsible for our own lives, and this is one of those times - she makes you feel awful, is a trigger to you, so you should be looking after yourself now. Do whatever it is to keep yourself on a more even keel, and making your own life happier. If that means letting her go, then do it. It's probably one of the most emotionally hard things to do is letting go of a parent, but the disappointment & hurt does calm down over time. It'll never leave you completely, but you'll learn to live without her, and without her negative influence, you'll live better.

Big hugs to you.