I am in a similar situation as you. I am currently in college but I live at home and commute. I feel bad about the way I treated my little brother when we were kids, and I feel that I never understood what it truly meant to be a big sister. We are six years apart and have very different personalities and interests, but that’s still no excuse. I’m trying to be better now and everyone notices it. I’ve apologized for being so mean when we were younger, but I still have a lot of work to do. I think that if you talk to your brother about it then he’ll be willing to work with you to try to get along better and build a better relationship. Apologize for the way you treated him in the past, and tell him that you want to try to be better. Hopefully he’ll understand. Maybe we can work on this together. :-) Let me know how it turns out.