Im gonna lose it

This guy I have know for some time has become a complete dick, and now he treats me like dirt. He has a girlfriend and last night he asked me to send him nudes and when I said no he got all pissed saying I should be glad he asked me, like I was suppose to send them. Then he has the nerve to say he wants to have sex with me because his girlfriend doesn't want to have sex yet. So I blocked him but I have a class with him every single day and today he treated me like a jerk and pretty much told me I was a whore. I'm two seconds away from smacking him in the face, but I feel like it would do absolutely nothing to help the situation.