DBing doesn't mean being cold toward your S. What you need to do is to be in friendly terms with your W, and letting her know you "get" that she does not want to be in the M anymore, and that you have a happy life of your own. See the difference? It's not easy to do. I failed at it many times.
You must convey that you understand what she wants and respect it, while being fun, and mysterious, and sexy, and all the things she liked about you when you first started dating. The change you're trying to spark is in her head. But only she can change her own thoughts. You're there to provide the fuel for that change. I hope you see what I'm trying to say.
