You may have to remove yourself if he’s ignoring your demands to stop hitting you. If you leave to a trusted relative’s or friend’s place for a little while, perhaps your parents and brother might see the seriousness of the issue. In any event, your safety is paramount. If you really are in fear for yourself and don’t think you’re getting the help you need from your parents, get out ASAP. At least then you can get some space to think about how you’re going to deal with these relationships and how to get on with your life.