Does anyone else feel like they suffer from a constant feeling of "regardless of how I feel about [insert member of the opposite sex], there's no way they could feel as strongly towards me"?

Basically, after a lot of introspection, I've come to realize that I struggle with the notion of believing/acknowledging that another person could love me the way I love them. I have a feeling it's at least somewhat related to two or three relationships I've had in the past where I guess I felt some really strong feelings for the girl, and then (for various reasons), the relationship was terminated somewhat abruptly, always by her. This sort of "rejection" feeling probably has something to do with it, and maybe what I'm saying is super common or maybe it's not all that common, I really have no idea.

I'm just wondering who else experiences these kinds of feelings. It's weird because I used to have no trouble at all allowing myself to feel deeply "in love" with someone else, but lately I seem to be subconsciously unwilling to do so, probably for fear of the bad things that can happen when you put it all out there.