you're in quite a situation lindseyiswicked.
All I can say is talk to your boyfriend and see how he feels about it, either way its going to be a difficult problem. If you decide to take the easy way and split up it might be hard for a while but it will get better as it alwas does, like you say you're only fifteen. But if you find your relationship is worth it (it seems pretty intense and you have been through some serious stuff together) you can be stubborn and try to stay together, you'll miss eachother like crazy and its no guarantee your relationship will stay the same, your and his feelings will change during your separation.
I have some experience with long distance relationships, since my boyfriend and I were separated for half a year last year. We both went to Japan on foreign exchange and I came back early. The whole experience was such a strain on our relationship (because I was terribly homesick and felt unhappy in Japan to the point of not being myself anymore and slowly sinking into a depression) that he actually broke up with me while in Japan,for about two weeks. I was devastated and got to a point where I was fearing for my mental and physical health that I made the (in my case) wise decision to return home after half a year. After making that decision it felt like a huge burden fell off my shoulders and I was able to come back to myself again and actually enjoy the remaining period that I had left in Osaka. My boyfriend of course noticed the diffrence and regretted what he had done almost immediately, resulting in a very strange and confuzing situation where we were 'together but not really',since I was going home and things were still a little strained between us since I stopped trusting him. I can't explain it better then that.
However, because things were a little better between us we kept in touch everyday, my boyfriend learned that he missed me a lot and I was able to put things in perspective. I can't say my feelings towards him haven't changed, especially when he first came back after 6 months it was very strange and we still had a lot of things to deal with, which we are still doing today. (as you might have noticed in earlier posts of mine in this thread) but after all I am happy that I was so stubborn and we both found eachother again in the end, however its no guarantee... when we were separated I adjusted to my life alone again, it was good for me since I found myself again, but it meant taking some distance from our relationship and from him. In a way I can say that our relationship might be less serious since. we still care for eachother, but in my case, I loved him, before we went to Japan, I wouldn't exactly express what I feel now as love...I would however like to get back to that point since I am a hopeless romantic and maybe naive and I strive to having a relationship where I can love a person and I know that person loves me back just as much. i know I am capable of that love and anything less then that is open to improvement in my opinion 😉
anyway, in your case I would advise you to take some time and think about what your relationship is worth to you, no one can do that for you and sometimes it even takes some time apart to realize whats the what. I would talk to your boyfriend a lot, boys might not like to 'talk and talk and talk' (I know mine doesn't anyway), but its really important that you are open and honest with eachother. If you both come to the conclusion that you want to give the long distance relationship a try, I'd say go for it (I'm proof that it can work) but know that it will take a lot of work and there are no guarantees.
I wish you all the best and keep in mind that if its meant to be it somehow will happen, might be corny, but I stick to it 😉
I hope my story/advice will be usefull to you and feel free to contact me if you still have questions or want to get smething off your chest.