I have to ask: What part of you was incomplete before you met her, and how were you coping? Would I have noticed that you were incomplete if I had bumped into you on the street? What would I have seen and did you actually know you were incomplete before you became complete? If you didn't know, was it an unexpected bonus to discover that someone else could complete you when you met her? How did she actually complete you?
Sorry to be a cynic, but each of us, standing on our own, is the complete package. We don't need someone else to prop us up as a crutch, or fill a black hole that should be bubbling with joy at any given moment. I don't personally want to take on an incomplete person so that I can complete her, so what's the benefit of being incomplete other than coming to leech energy and generosity from your partner?
Lets be complete in ourselves. To be sure, joyfully share our completeness with our complete partners, but: "You complete me" sounds pretty sad to me.