I'm so sorry. How painful, I think, to have a sibling who is toxic like your brother seems to be.
I also want to point out that being sexually active is perfectly acceptable as long as the people involved are adults and the sex is consensual. I would not refer to being a sexual human being as "sleeping around". And choosing to have sex - I don't care if you have sex 50 times a day - has absolutely nothing to do with rape. Rape is a crime of violence, not sex.