In love with my best friend?

I have a friend who is a male, we’ve been friends since the summer after our freshman year of high school. We are now freshmen in college. We went to different high schools and now different colleges, so most of our communication is over Snapchat. We always used to talk non stop, but now he leaves me on delivered for hours. We have recently hooked up, we’ve only done it once, but I can’t help but think that that has something to do with it. I’ve grown such strong feelings for him. Feelings so strong that I cry at random times when he doesn’t respond to me, as childish as that sounds. I’m fed up with it. He says that he loves me (platonically) and that he cares so much about me, but when we hardly talk, it makes me feel so sad and I don’t know what to do. Help?