I understand that it can feel scarey to talk to people outside the family about this kind of thing - although I never suffered physical abuse, I did suffer other types, even now it is hard to accept that my family could ever have been anything but nice to me. It just sounds really worrying and dangerous that your brother can put his hands round your neck to the point of unconsciousness. This is a site that cares about each other and I care about what happens to you - I wonder what options you can think of that may help to keep you safe?