Something missing in my relationship

I've been with my girlfriend around 14 months now and things have been going great, nothing is specifically wrong with the relationship such as cheating, distrust, arguments etc but recently more and more feelings of "boredom" with the relationship have started to arise, I love the girl and she's amazing but I think now that we've both finished our A levels and have the whole of summer, the fact that we are so different is affecting our relationship. We are both (hopefully) going away to uni in September and I’ve already made it clear that a long distance relationship is not what I want. I don’t want to hurt her in any way because she has stuck by me through some of my hardest times, but I feel im ruining our relationship anyway due to how distant I feel im being, any advice would be greatly appreciated
Thanks

Well seems like you should break up with your girlfriend, cuz I'm - oops, "you're" - bored