Is it normal i can't stop thinking about him?

Over this last summer I did a study abroad program in France and I met a beautiful French boy. He really liked me, and I really mean that; he would always look at me a certain way and he constantly told me he thought I was "beautiful" from the first day he met me (we were together for two weeks). But it's not only that; we have a lot of things in common (we have the same taste in music, we are both the youngest children of our families, we like the same movies, etc.). At first, I wasn't really interested in him because it seemed to me like he was only interested in me since I'm "foreign," but once I realized how similar we are and how genuine he is I started to like him back. Anyway, we hung out a lot while I was there and then on the last night before I left to go home we had this very romantic (that sounds cheesy but that's what it was) night together and we kissed for the first and only time (but we didn't do anything more than that). Anyway, he kept on saying (even before we kissed) that he would come to America to visit me and that he would write me on email, but then I left...

And believe me, in the back of my mind I thought that the words he said weren't true and he was just trying to "hook up" with me, but then he emailed me immediately when I got home in America. He even tried to visit me here, but it didn't work out. Also, when we kissed he was so sweet and it didn't feel like a "hook up" at all, at least not to me. I never wanted to have a "long distance relationship" but I hoped we could at least keep up contact until our paths crossed again somehow.

Anyway, in the past few weeks his replies to my emails have been slowing down and now he's not replying at all. And I know it's not because he's too busy since he is still active on his facebook. I guess I understand if he's "moved on" given that it's been almost 3 months, but I really can't? I'm just so confused because I felt something with him that I have never felt with anyone else, even though we were together for a relatively short time. I'm really trying not to be obsessive over this, but somehow I can't stop thinking about him and it's driving me crazy since it seems like he doesn't feel the same way anymore. So is it normal that I still think of him and dream about him constantly? Also, does anybody have advice on how to get over him since it seems impossible that anything could ever work out between us now?

By the way, I am 17 (he's 19)