How do i maintain a long distance relationship?

my bf and i havent been together long. we're both in the bahamas but we live on different islands. i'm unable to visit him (due to circumstances beyond my control), but he comes here every once in a while. meanwhile, i have a friend dating his best friend and she goes over there alot. i always hear stories about the great time they all have, while i'm stuck here missing out. it makes me feel terrible, knowing i can't travel like they do and see him as much as i'd like to. i feel like i can't keep up, like i'm not doing enough to keep him. i know this may all be in my head, but i'm so worried. i can't imagine how he feels when his best friend's girl visits while i can't. i'm sure i sound insecure right now, but he's just too great to lose. i wish i could talk to him about it without sounding crazy. how do i bring it up?