How to get unattached?

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 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 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!!