I'm with but I don't know if I should be

hi, my names Lillie and in the last years I've been having a long distance relationship with my boyfriend in Andover. Lots of people have said to me im lucky to have had such a long long distant relationship at my age (16 almost 17). When i was 14 i was in a well not a relationship but i was going out with him (my present boyfriend)and we lasted so long, we never 'broke up' or had any arguments we weren't clingy to each other and we went out all the time people thought, after a year, it was to good to last. Then 2 years after we got together my step dad in the army got a stupid posting to another country but my boyfriend he was to in love with me to let me go and i loved him also so much so he had the idea of a long distant relationship and i agreed. Now every time i go back i see him for a couple of days but i don't think its enough because is best friend is also a close friend of mine and well he thought i needed to know he was spending and awful lot of time and getting very close with a new girl at their school. im worried hes gonna break up with me for her even though every time we speak he tells me he loves me very much and this is like everyday, and i move back in 2015. so all im asking is if i should talk to him about her of end him or what this is driving me crazy i love him so much and apparently he loves me too what do i do please help!