Wanna give me a hand here?

How do you break up with a woman who appears to be totally crazy about you? I'm pretty much ready to do it I think. As these things always end, it's sort of a matter of "I'd rather be alone than be with you," always a scary message to have to code and deliver to another person. She's away for the week, but she'll be back by Sunday and I'd like to do it very soon. Your suggestions as to how this should be accomplished are welcome.

The problem you see, lies in the narrative. I am (not was, am) infatuated with the blonde, something that is obvious to anyone seeing us together. We're that really annoying couple making out at the bar, on the street corner, movie theatre, barbeque and just about everywhere else it's possible to make a spectacle of one's self. We have sex that's spectacular, look good together and generally have fun around one another. But it's completely empty, sometimes cringe inducing and very expensive (which considering that I've been unemployed till very recently makes me question her sensitivity). Anyway it must end but that end is going to come as a surprise because there's been little in my behavior to indicate that it was coming.