Boyfriend going into the Navy

Alex
Im 16 he is 17 almost 18 but he is a senior i am a sophomore. Needless to say he is graduating this year and we have been together 1 year and 4 months. He has decided that he is going to go into the navy. I remeber when i was younger i told kyself i wouldnt date anyone in the military because i thought i wouldnt beable to take it. Well anyways here i am many years later. I want to support him. Its just he never really wanted to go into military until a recruiter came in and that was a few weeks ago and he now has his heart set on it. We plan on continuing our relationship. But im just having a hard time coping with him going out of state and having limited communication. He is signing for 3 years but plans to sign again after that for another 6-9 years. I just hope we make it. I just dont want to be alone. And all military wives i dont see how you can be so strong. I feel like if we do make it ill be a conplete mess missing him. Anyway sorry for the long rambly paragraph. I just need to know how to cope and accept.