Hey Mark,
Thanks for your great advice. I can certainly identify what the need is: I need to find my significant other, someone to share love with. At the risk of sounding terribly cliché, all my other needs are (partially or wholly) fulfilled. I have everything I want, except for someone to share everything with.
In a way, yes, I guess I'm attached to the idea of my friend fulfilling that need - I suppose my dreams and fantasies about our imagined relationship act as a surrogate for the real thing.
Which, rationally, gives me all the more reason to want to move on. Why can't I just fantasize about someone who is more available to me?
@Akashic: some day, I might believe that I'm in complete control of everything I experience... but I'm not there yet, not by a long shot