Lose all self-esteem, greet him warmly and politely, and invite him to dinner whenever possible. If you can solve it, you must try your best, because it is possible that when you graduate, he or she will find many problems with you. It's not that this teacher is like this, but that you left a bad impression on him and it's easy for people to find fault. And as a student, after all, the teacher is humble, and offending the teacher is his own reason and responsibility.