How to get unattached?? More details?

Ok so I met this guy 4 months ago. He is amazing but lives in oregon and I live in Tennessee. Well we met on a cruis ship kissed. We kept in contact but at the end of January I stopped txting but then he txt me the middle of February and said he had feelings for me again an missed talking to me. So we started talking again. We are never gonna be together because we don't want to do the whole long distance thing cause we would never get to see each other until maybe college in a year( he has told me he will def be with me when he goes to college but who knows alot can change in a 1 so I'm not getting my hopes high). But then still we will be kinda far away but closer. Well I'm a lil attached. I like him alot but i dont want to be attached then get my heart broken. I don't know how to get unattached? How do I get unattached when I like him and he is so sweet to me? Help please!!! I don't want to be attached anymore!! Is there anyway I could get unattached with still talking to him? I still want to talk to him once in awhile cause he I a good friend!