Thanks for the responses. They've given me a lot to think about. There are a few things I didn't mention in my post that might shed some more light on my situation:

1) I'm on sertraline right now, which I suspect may affect how I feel about physical affection. I understand that antidepressants often blunt sex drive, and I wonder whether it's possible that they dampen people's desire for simple things like cuddling as well.

2) I'm not completely over my ex-boyfriend. I am very aware that I need to move on from him and that things will never work out between us. But I still feel hurt and rejected both as a result of the initial breakup and the back-and-forth that happened afterwards.

3) As painful as the situation with my ex was, it did teach me to never base my happiness on another person. I was very emotionally dependent on the guy, and went into a deep depression after our breakup. So I'm wondering whether I'm trying to protect myself from becoming too attached to my current boyfriend.

Anyway, I'll probably respond to certain parts of your posts later. Just wanted to mention the above things since I think they're important to understanding my situation.