1. Fight the murder drive. 2. Breath. 3. Take my advice from here on with a grain of salt since I'm lesbian and also have never been in a relationship or had a crush. 4. Is it that he doesn't like you or doesn't know you? Either way, I'd try just bein' nice around him, don't shift your whole personality, but just act a bit nicer than you usually would. Eventually try telling him you have a crush on him.