I met a guy in the states early 2013. We hit it off really awesome and it was pretty clear we were in love. I had to come home (to Australia) that June and we decided to do LDR.
My advice:
be prepared for ANYTHING. Two close friends lost their lives within a few months of each other and I went a bit nuts. Partied too much, took a few drugs and ended up doing some things I deeply regret. I wasn't honest to him about them mostly because I was embarrassed and ashamed and I didn't want him to be worried about me. The distance meant it was easier to hide things. I wasn't prepared for the stress of close friends dying as well as a LDR. Having said that, we were half a world apart. FYI: I came clean about everything late in the year and it was just an awful mess that I will never put anybody through again. I lost a good friend through it. Honesty is the best policy when it comes to these things.
talk ALL THE TIME: you must keep the conversation flowing as in a non-LDR. Even the really boring shit. We also sat together over skype and watched movies/TV shows just to keep that bond going. Love is one thing, but to have a proper relationship you gotta be together even if not in a physical sense.
be madly in love such that you cannot stop talking to everybody about them. Keeping them in your mind is important and the minds of those around you keeps them close to the top of your thoughts.
Not gonna lie. College is a time of huge change in life. You will be exposed to some fantastic new thoughts, ideas, experiences and some really really amazing people. You (or he) may find somebody else. This is not the end of the world either. It's all part of growing up, becoming an adult and realising who you are! Change is not a bad thing!
It sounds like you have found somebody you really love which is awesome and I wish the absolute best for the two of you! LDR is not ideal, but it does work! My boyfriend moved to Australia and we have had an amazing year and a half together down here. I am moving to USA in 6 weeks with him to see where else this path leads. All the best!