Am I into him?

I find that a few days a month, I tend to freak out and reevaluate my relationship and jump to the conclusion that I want to break up with him (he hasn't done anything to necessarily set me off). Other times I can't keep my hands off of him. I've never gotten butterflies with him, but we've been having pretty decent sex and I do feel attached to him. Am I alone in feeling like this? Not sure what all these emotions means!