How do I regain my reputation?

that was mean for him to do that, just ignore them if you can or if you are in school ask your parents if you can transfer to another school. stay away from the people that are upsetting you stay by yourself if necessary, i know that you don't want to but this may be the only way to regain your reputation. don't interact with the boys because like you said they will only think you are easy and you don't need that.