You can't hide the truth to protect your abuser. If telling your brother or other people about the abuse hurts the abuser's feelings, that's not your fault. You didn't create this awful truth. He did. The guilt is his to live with. It's not your responsibility to protect him from it. If it hurts your family, it's not your fault. You didn't do anything wrong. This secret is should not be controlling your life. You're not the culprit here.

I know you're worried about your family, but your home doesn't seem to be a very safe place. Letting the truth come out should make your home safer.

You need to start protecting yourself emotionally -- allow yourself to health through therapy. Since you're in school - university I presume - you should have a student health center with free mental health services for students. It's important that you see a therapist about these issues. The feeling of estrangement from your family and wanting to run away are signs that not everything is okay for you personally. Trauma isn't something we're meant to handle alone. We need support.

It's always wrong to touch another person without consent and your brother had to have known that. If he shows a measure of self-disgust, it's only more evidence that he knows he's wronged you and your brother. Unfortunately he's shown a pattern of violating boundaries, not just with you. The truth will out and that's not your fault.