I'm sorry you find yourself in this predicament WK.
It seems to me a matter of lust vs, love, as you've said. If I felt the way you do, I'd choose a course of action soon, otherwise the choice will make itself for you, and I like to be in control of my own life so I don't feel like an idiot later. Whatever the choice, I didn't let time step in and handle things for me. That's a cop out.
And completely off course, can I just say it's nice to hear several of the men say that there is no excuse for cheating. It's quite refreshing!