Happy New Year Paco ... and sorry it has been a while since i last wrote. I hope you are well and that the holidays have been good to you.
I agree with everything Kiro says above. You are not, and will never be the WAS. The marriage is over (for now) so, if you walk away, you are walking away from something that is no longer there.
But I do understand how you feel ... there is a part of me that feels, if I drop the rope and move on, I have failed ... that I DID NOT TRY HARD ENOUGH. I lack the courage of my convictions. But these are foolish thought. When, and if, I drop that rope I know deep down I did everything I could to save our marriage. Some of the things probably did more harm then good, but it was with the best of intentions and by someone who deeply loved (loves) their partner and wanted (wants) desperately to save their marriage.
Personally, I do not think that the decision to move on will be a conscious one. It will just happen - not with an epiphany, but with the gradual finding, and liking of ourselves, without our spouses. Not with hatred, resentment or anger at our WAS, but with an almost unconscious acceptance our MR is over and a realisation that the emptiness we once felt no longer feels like emptiness.
Which nicely brings me to your 'void occupied' / 'emotional space vacated'. Paco, I know you know that this space/void cannot truly be filled by another person. You must fill it. You and you alone must learn how to feel comfortable in it. You must learn to love yourself. Until then, other people are mere distractions. Don't get me wrong, distractions do very well at well at .... distracting, but in the end we must all face the mirror. I read your post, and I sense a deeply intelligent and articulate man who is acutely aware of his W psychological and emotional well being. But other than your grief and your desire to understand your W, I get no sense of who you are. Shine the light on you. Take a long and honest look, not at your W, but at you. Know and take responsibility for your part in the breakdown of your MR. Until then, any relationship you have, whether it be with your W or someone else, will be flawed.
Sorry if that sounded harsh. I don't mean to be harsh. I respect the thoughtful and intelligent way you write, your commitment to your W's healing and your decision to stand by her whilst she fights her demons. I know when you look in the mirror, what you will find is a good man, who, though flawed, love(d), and in his own way, was/is devoted to his wife and was committed to his marriage.
