First of all, have you voiced any of your concerns to him?

As an overly clingy person myself, it disheartens me that I might have come across like that. In my case, it did calm down and even out over time (we've been together 2 ½ years). In my case, it came down to very low self-esteem, a disbelief that anyone would want anything to do with me, and a desperation not to lose the one person that actually listened to me and made me feel heard and loved. I have no idea if that's the case for your boyfriend.

I also was uncomfortable with the thought of him possibly going away to work in the summers. I was just afraid he would immediately meet someone more attractive and suddenly stop talking to me. See, low self-esteem and also trust issues in my case. He hasn't had the opportunity to be gone all summer for work (maybe a week or so at a time maybe?), but I really hope it wasn't because of my insecurities. My point is, do what you want/need to do and either he gets over it and works through his insecurities (or whatever the issue is) or you might not be right for each other. That's just my opinion though...

But you do need to talk to him. It may be a difficult conversation, but I believe stronger relationships are built on the occasional and necessary difficult conversation. That's at least been the case in my experience.