Anxiety and boys?! Help!!!

This guy asked me out when I was in grade 8 and he was in grade 7. He said he liked me and I said I liked him but as a friend. I was 14 at the time and didnt wantti date anyone. He told everyone we were dating! They didn't believe me when I said we weren't. We had been friends for a year. 1 year! He has no right to do that. He barely knew me. Then I graduated from grade 8 and he didn't text me at all over the summer and I texted him at the very begging but gave up. Then before grade 9 he texted saying he loved me and he missed me and that he broke his phone. Then I said we are just friends and he probably thought I broke up with him over text because in his mind we were dating when really that's just what he thought. We weren't dating! Now I'm in grade 10 and he is at my highschool! He doesn't even live in the right area to go to my school. He lives in a different school area and should be going there instead! Oh! And to make it all better! I'm stuck on the 1st floor this year which is where the grade 9's are but now everyone is all over the place. AND he has been in my hall talking to one of his friends and I'm not sure if he noticed me. Plz help! What do I do if I run into him?! I haven't talked to him since the the summer of 2k15