This Guy asked me out... But i don't wanna go out with him! What do i do?

Ok so im gonna give you the WHOLE story. Yesterday i was at my locker getting my stuff and about to head home when my friend Rhianna (no joke) comes over and we start talking about a movie. All of a sudden this guy, (Lets call him AH ok? you know for hole?) AH comes over and says out of the blue, Wanna go out? so i just kinda sit there dumbfounded and say very calmly, No. He gets closer to me and repeats it. I say no a lot more firmly now and he comes even closer and repeats it again. i say NO tons more firmly and he gets so close to me i could put a pencil between his nose and my nose and it would stay there. and that's a pencil that's already been sharpened like 2 times. So hes going to say it again when i book out of their and down the hall and into the bathroom. and i run FAST! so i was in the bathroom and missed my last period and he just WAITED out there. i hid in there for the whole afternoon and missed my bus home. So i go to school the next day and he sits behind me in cl and just KEEPS ASKING ME! finally i faked a bad stomach and was able to throw up (do not ask me how) and i got sent home... PLEASE HELP!