Just keep in mind what detachment really is. It's releasing from teh eventual outcome of the M. And that will come once you truly accept that you have no control over your W or her decisions. And that takes time.
Your brain will accept that pretty quicly b/c it makes sense. Getting your heart to follow takes a little longer. Not b/c your heart disagrees with that statement, but that it doesn't WANT to accept it. You have to be patient for yourself too. Just keep walking towards your goal, and you'll get there.