I too have had a family which excluded me and my children in various ways, many times and have been set up as the family black sheep, the one who is different.
Too right I am different. I don't operate like a bully with a group of sycophants behind me. I would not be so cruel and hurtful or leave family members out. It hurt - a lot, as did the snipes, teasing and lack of understanding.
I say this in the past tense as I do not see the ones who have been so hurtful, caused me so much pain. I had to leave them to it for my mental health and self esteem. I love them, I miss them, but know if we were in contact it would all start again.
We exchange birthday and Christmas cards, that's it. My half brother doesn't bother but we were never that close.
I have enough of a life away from them all and live a few miles away so that it is bearable and I am ok. I know I feel self respect and not constantly got at and I leave the others to stew in their own juices as they can't now reach me and leave me with sleepless nights and worry any more.
I agree OP, certain people leave you with no choice, they make the decision for you. You will go when you feel it's the right time, when you reach your absolute limit. And then you will be free. Free of it all, free to live your life how you want, free from the pain of it all and you know that they are the problem, let them deal with their spite and pick on someone else.