I suspect finalizing the divorce may actually be harder on your wife than on you because of all the work you have done. Many here have said it, but when it gets down to it, it really is just a piece of paper. I am not minimizing the angst that goes with this. You have been an inspiration to us all and continue to be. You are walking the talk and it is paying off.
In some weird way finalizing things can feel like some weight has lifted from the situation. This was true for me. My D was finalized this past July. I don't know how to explain it exactly. I think it is the only way my ex could really begin to do his work. He is not happy or relieved now. He told me last night that he is trying to learn how to forgive, including how to forgive himself. (Before this was seen as weakness for him). At any rate, my point is that maybe it will take this step for your wife to really fully comprehend that leaving your marriage did not fix her. She may not have been able to convince herself of this in any other way.
You are doing great. And you are very helpful to others. Stay your course. I think you have more chapters in your story with your wife.