Had a fight with my art teacher today, heaven knows i have a great deal of respect for him but he can really piss me off. I made the mistake of taking out some of my lion king drawings out during class and he got really made at me and called my drawings crap. It really hurt, even though i know he only said it because he only understands realism. But that didn't stop it from hurting.
I am sorry that your teacher insulted your work and possibly humiliated you. It wasn't right for your art teacher to say what he did. Sure, he was trying to get you to learn realism, most likely assuming that was one of the "realistic" drawings you created. I am not quite sure. However, I want you to keep in mind that you are a talented artist, whether it is through realism or not. You are skilled at both.
I hope you feel better, seeing to it you took his offensive comment rather harshly.