<human>: Can you summarize the given text in a few sentences?

So my boyfriend and I met in high school and began dating right as he went off 6 hours away to college. Long distance wasn't too bad, and he came home about once every month or two to see me and his family, which was tolerable.

Fast forward to now and I'm in college as well (about an hour and a half from our hometown) and I'm not sure if this relationship is what I want. My boyfriend is a GREAT person; so adventurous and funny and sure of our love (even though I'm his first GF). I love him SO much but I'm not sure if I'm still in love with him.

I'm not the cheating type, but with so many guys around it's hard not to develop little crushes or wonder what it would be like if I was single. This is probably "grass is greener" syndrome, but then I wonder about stuff like

-the fact we don't have an end date for long distance (he plans to get a job where his college is after graduating, and I'm not sure if I want to move there)

-we see less and less of each other as time goes on

-when we are together, our sex life is not completely fulfilling to me

I see that a breakup is probably imminent, but I don't know how to go about it without completely catching him off guard (although these are all topics we talked about, we have never come to solutions on any of them) and totally breaking his heart.

Like I said before I'm his first girlfriend so he has no experience with being dumped; I'm really not sure what to do. I love him but I don't think I want to be with him enough to keep this going. Any advice?
<bot>: long distance relationship is getting hard to deal with but I love the guy, should I stay? And if I shouldn't, how do I limit the pain he feels from a breakup?