My grandfather molested me as a child?

When I was little, my grandfather molested me. I don't remember the first time it happened, and I can't remember him not doing it. I must've been very young. I think my age was around 3-9/10, so it happened for almost a 6/7 year span, so it was normal. When I was 9, I started to realise I didn't like it, so I asked my brother if it was wrong and he said Yes, and left it at that. I remember being angry at my gpa whenever he tried it after that. I remember telling him he should be doing it to gma, not me. Anyway, I'm 13 now and I've just recently told my 3 best friends. I don't know what to do? No-one knows but my best friends, if I tell it'll rip up my whole family. Please answer.<3<3