Relationship advice

Hello! I am 25 and have been seeing my boyfriend, who is 28, for 4 months. I have been on serious, long term relationships before- but now I truly believe in "the one." I know he is the man I will marry and we are always talking about how happy we make each other. He is divorced, and the ex wife had a child with another man. 
My lease is up in March and we have vaguely spoke about me moving in with him at that time, and I would love to do so. At the same time, he has said he fears failure in another marriage and sometimes says things like "whenever you renew your lease or whatever you're going to do in March" which makes me feel that he is not thinking about it as much as I am. 
His parents adore me and mine adore him, we are going on a week long cruise together in the West Indies in January. 
We spend every night together, whether it is at my place or his. I sometimes have a hard time being peppy when I get hung up on our future, which I am afraid to talk about because I don't want to seem too hurried- but we both acknowledge that we are special to each other. 
How can I make myself ok with just letting go and letting the future happen as it will?