Hi Barbie
Fascinating diagnosis. I've read and chased up a couple of the articles and the links.
The one thing I can assure you of and I mean you as a sole person - not as wife or mother - is that now you have greater clarity, you are absolutely right to now completely focus on you, your needs and your future. This diagnosis and your H's therapy allows you the freedom to stop wondering or thinking about it any more.
It gives you the permission you had been denying yourself to take your eyes off him, off the concept of MLC and off the wondering if you would ever reconcile properly despite all the work you are both doing.
Speaking radically (perhaps too much for some) I would almost go so far as to suggest that you stop listening to Retrouvaille or reading any more about MLC marriages/reconciliation etc.....
All of that has to be put on the back burner for now. Your H has a diagnosis for now that seems to answer many of the questions you have had.
Now is the time for you to forgive your earlier self for not noticing, for not understanding, for your anger, your own PTSD and your own self frustration.
Now is the time to understand that your grief on your father's passing is still there and you give yourself permission to work that through without thinking about anything else.
Now is the time for you to allow your marriage or rather your R with your H to breathe all by itself with no active engagement or feeling of "should/must/need to" etc....
You know this - your marriage with your H died the moment he left. You now have an R in which you have worked so hard to restore back to a marriage but you now know that there is much more to be gained from a marriage and you especially have not received those gains. So step back fully from the R and allow it to just chunter along without any decisions or any feelings of what is not working.
And also forgive yourself for thinking that that little voice in your head which kept telling you to leave was wrong or bad or that so doing would cause more harm than good and also for wishing that you had listened to it.
There is now genuinely nothing you can do other than allow yourself to breathe properly - to love yourself and to continue to grow just for you.