Dear Jordy,
I am so sorry you were sexually abused by your brother. But what's worse is that he neither has apologised, nor your mother is taking it seriously about how traumatic it must be for you to face your abuser every week when he isn't remorseful for his behaviour. I'm so sorry that no one understood your pain then and they are not understanding it now.
Does the boy's mother know that he abused you?? If not, I think she should know. Because all abusers are narcissists and the baby's mother should know that she's leaving her son with a potential abuser. Tomorrow he may abuse your nephew. If he's not being a responsible father....can you get child support involved??
You don't have to go thru the torture of seeing your abuser every week, especially when you are healing from it. Maybe you can just volunteer at some place every saturday - church or animal shelter or some old age home or children's home....or maybe you can join some weekend class (you'd gain some skill and avoid your brother).
Or, you can just take buses to some other city, eat there and come back to your home....provided you love bus journey. May be you can travel to some place, take pics and maintain some travel blog.
Don't face your brother if it hurts you. Avoid him in any way you can.
Hope you can work this out with your T.
We're here to help....Good luck!!