All your replies help me to gather my strength. The difference between how I feel now and 2 years ago is that I do see through the manipulation, emotional abuse. I see it, yet, part of me is conditioned to still feel it's my fault.
And I keep wondering: why do I need to explain myself to my AH, or his father? Why do I need to tell them why I can't allow him back in my life? I am past the phase where I wanted to control others' emotions, including other's feelings for me. It's not that. In the absolute, I don't care of they think I am selfish.
The sad truth is this: I live so far away from my own family (I am french and live in australia), that my AH and his family are the only "relatives" I have here. And if I become sick myself, I can't help but think:"who will support ME?" I feel so alone! That is what is holding me back in all this....