What should i do with my long-distance boyfriend now that i'm starting University and he's just finished?

My boyfriend and I met in the Netherlands while i was there visiting my father. I was 16 and he was 20. I fell in love with him that same summer and we've managed to keep a relationship for the past 3 years even though i live in canada and he in the Netherlands. I am now turning 19 and am starting University in Canada in September. He just finished University in the Netherlands and is an architect. He was recently hired for a job in Prague in the Czech Republic and has asked me if I would eventually marry him. I have no idea what to do! i think i'm too young to commit like that but i love him more than anything. he is 23 and starting to build a life for himself. i really want to be a part of his life but it is hard since i am in canada. should i continue with this relationship? sometimes i think it would be easier if i let him go and move on especially since it is only going to get harder now. but i am afraid that he may be the love of my life. should i keep going? help??