Heim-- You mention the past roles of who did what in your M. You have to let those go, and take on all of the roles that are needed as a single Dad, without your W's input. She needs to see that you can do this all on your own. And you need to feel it, too.
That is when she might start to miss the role/place that she played in the family.
Come on over to Sep when you are ready, or stop by to read my thread. You'll get a double-dose of OT, along with some other great advice that I bet would apply to your sitch, too.
Just don't be too hard on yourself. Making these kinds of mental adjustments as to who we are, and where our spouses really are, come in time. They unfortunately can't be rushed.
