Mother and brother won't speak to me. What can I expect, and what might I do that's a healthy choice?

[Joanna]

"I've always needed her approval regardless of her ill treatment of me" I can understand that completely.
Although my family are less extreme, I seem to fill the same role in my family that you do - I am always the one pandering to my family members in order to get their love and approval.

It's difficult to know what to do. What is your dad's opinion of what has happened recently? Is he interested in your son? Perhaps talk with a neutral member of family - your mum's sister for example. She might be able to make your mum see sense in a way that may make her realise her actions towards you.