<human>: Basically, I'm worried that I'm ruining a perfectly good relationship by overthinking it. We've been together for close to three years and are each other's first everythings.

There isn't anything wrong with our relationship (that I can tell, I guess have nothing to compare it to). He's sweet and funny, I'm always happy when I'm with him. Sometimes he has problems expressing his affections, which is where I think my problem started.

Basically, he's more or less sure we're going to get married someday. He doesn't shower me with I love you's or say that he misses me when we're apart for a week or two because he's so confident in our relationship that two weeks seems like a blip in terms of the years we have together. 

I'm not as sure as he is. I love him now, absolutely. He makes me so happy and while he can be a bit of a homebody, I always have fun. But I don't know if I want to marry him. I'm 22, I don't want to think about that stuff until I'm 25 at least. If we're still together we can have that discussion then.

The problem is, now I can't stop thinking about the fact that we are either going to be together forever or we're not. At this point in my life, both options are terrifying. How do I stop focusing on the future and let myself enjoy this relationship for however long it may last?

He knows I'm not as sure as he is about marriage, but he's still sure, and I think his confidence is making me even more insecure because if he's sure, shouldn't I be? I don't know.

Give me the gist of the text in a nutshell
<bot>: Boyfriend is a lot more confident about the future than I am. How do I stop feeling like I have to choose RIGHT NOW to break up or be with him forever and let myself just enjoy what I have?