Beachkoala, I saw you post on ICR and just want to offer anything that might help you at this time. I had read out loud your heartbreaking last sentence to my SAWH (Sex Addict Wayward Husband) this morning, in hope that somehow the truth of what he did to US might be reflected back to him in a new way (not my tired words he's heard a thousand times and ignores): your eloquently expressing the felt death of your marital bond FROM YOUR PERSPECTIVE.
Sadly, as I've been stuck in this IHS for way too long - for all the wrong reasons - I've come to believe people like these truly lack the ABILITY to put themselves in another person's shoes long enough to "feel" the impact of their horrible choices. Also, the kind of emotionless infidelity they get into further dulls their human capacity to perceive, as does a lot of pornography.
I tried all the MC, book reading, talking, interrogating, waiting for noticeable change, for openness, for honest emotion, and did books' worth of internet searches (before SI! Sure wish I'd found this site in 2002-2003!) while I decided for economic reasons to socially provide him a second chance, even while we did not resume a marital relationship, so as not to blow up both of our lives totally...until 12 years later, when he was arrested ON MY BIRTHDAY for solicitng a prostitute! All that patience I granted him simply bought him more time in my life to be who he always was.
The property settlement I went for after his arrest divided real estate and bank accounts; not only was it a post nup, I had the lawyer include a timeframe for executing deeds of gift for the transfer of assets to "within 30 days from the date he would sign" my prepared "Marital Agrrement" (to stay legally married under the circumstances, as HE wanted. I was DONE after 17 years of THAT sorry M!) I wanted to get a preliminary D agreement in writing during his post-Discovery "shame cycle," while he was waiting for his court date and was expressing Regret to everybody, friends, neighbors, church, for being such a creep). It made the nightly local TV news!
Please don't follow my example, no matter how you handle this trauma. I tried toughing it out for well over a decade, and all I got besides the real estate is older and sadder. Internally, the change that my SAWH needed to make, he could not or would not. NOT that he continues to act out sexually...just that he lacks the ability to perceive, to deeply care, or to reciprocate. It's no way for us to live! The flat personality issue might predate the infidelity or it might be the result...not for you to deal with sorting that out. You are more valuable than that!
Sex addiction clinical therapist Patrick Carnes wrote a lot about these cases and said if they can make the deep changes they need to make, eventually their partner will detect it, but I never have been able to positively identify such changes, I just haven't found out any more damning evidence (in the last 12 years...but what about the 12 years before THAT? Same story!)
I really recommend finding a trauma-informed counselor for yourself and consider that the intimate bond has been destroyed, so while you work on healing and he works on his character flaws, etc, it will not turn into a fake-it-til-you-make-it act for YOU as it did for me. Believe me, they want that outcome! Can you have him move out? And see a few good lawyers, just for a "consultation." Around here, it might be a fee of an hour. Just ask for a family lawyer consult, don't ask them to be a Divorce attorney, just yet. And proceed better informed. Take back your power!