Your post describes exactly where we are in our 3rd marriage right now, although it all makes so much sense and completely describes my H, I feel like a failure walking away yet refusing to live as roommates and H. not willing to go to marriage counseling.
Me 53, H 54 together (4) years in individual therapy
H: 44, Me: 45 Married: 20 y Together: 25 y no kids Walk away: 12/15 Asked for temp separation 12/25/15 PA confirmed 3/16 (apparently neither the first, nor the last PA he has had) H filed for D 5/16
You may continue to wait, but also continue to move forward and leave the door ajar. Continue to work on yourself and try to keep the focus on you. It's hard to determine at this time if your w is in MLC or a WAW, but we use the same strategies for both. Space and time are very important when dealing w/someone in either situation.
Dig deeper for patience and like I said above...keep the focus on you.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.