I support you transfer to another school if you could. Not every American professor is nice. I can understand your feelings. You should be self-confident just like before. Don't waste time under a poor teacher or in a poor school. Only one suggestion is that you have to be careful and think it over before you transfer this time. And before you transfer, study English hard as possible as you can. Don't waste time anymore. Language skill will help you a lot wherever you are.