Can you give me your opinion on long distance relationships?

I'm 15 years old and I was an exchange student last year in the US. I loved it I really did, the thing is, I fell in love with someone. I never really thought he liked me back, but a week before I left I told him how I felt and he told me he liked me too. I didn't expect him to say that, let alone suggest that we should be in a long distance relationship, so when he did, I was really really happy. Now I'm back in Mexico and I've just been thinking a lot about what's going to happen. I know I love him. Since the first moment I saw him I felt something inside. He makes me happy and it's like whenever I talk to him everything's just a okay and I feel like this song playing inside my head and I feel like life's actually good and worth it and I love everything about him, I really do. He says he loves me and all, and I trust him, and he's sweet and nice and everything you could ever want but I'm just really scared. I mean, what's going to happen now? Sure, I'll be visiting in December and then the summer after that, but like, what will be the outcome of it all. I know it sounds stupid, but I really don't want to be with anyone else unless it's him. What do ya'll think of this all? What the hell should i do? :c oh dear everything is just so confusing right now and i know it's all in my head but I can't help it. I'm sorry my English isn't really great, I really am. Hope you're having a nice one and thanks for answering x