I love him! what do I do?

I know i already posted this but i forgot to mention a few things.. So theres this guy, he was sweetheart to me and showed signs that he liked me sometimes. We became really good friends over the school year. Another thing is though, he is the kinda guy who has had a billion girlfriends and is kinda a perv. He has dated a few of my friends and it ended terribly. One day, he asked me to prom. Prom was the day before school ended.. so I spent forever getting ready... not realizing that i would miss him after school ended. Prom came and went, we danced the night away! During the slow songs he held me tight and said i looked beautiful. I could tell in his voice that he liked me and everyone thought we were super cute and that he was going to ask me out. I couldnt stop smiling. He acted and talked differently with me then he did with my friends who he dated.. The last day came and we hugged goodbye.. I could tell he was sad and I cried. He sadly asked me to text him. Ive been crying all day for the past 2 days... I knew i was gonna cry.. but not for this long! I knew i would miss my friends but i think im only crying because of him... maybe i need closure? Not really very sure! I'm not sure what to text him or what to do? Next year is high school, and the school is big. What happenes if he forgets me and gets a summer girlfriend? Or he doesnt talk to me and forgets his feelings for me? Please help??