Did a quick read...very close to my situation actually...H was not a cross dresser but had suffered severe physical, sexual, and emotional abuse by various family members...his own F sexually abused his own daugther and step daughters...was abusive H and alcoholic...when H started to break apart he was running from his past...this could be where your H's cdg fits in...
I know my H hit bottom in terms of depression...against the normal DB'ing advice I would at different times extend my hand to him...offer allow him to come home...he also went NC for months at a time...both of our D's refused to speak to him...one continued this course for about a year after he was home, as if he didn't exist...he never planned to divorce me either...he also had online A first...years earlier, which looking back was probably a sign of things to come with MLC...and like you said, my H would be the last person anyone would ever think of having an A...
Alot of similarities, including us being high school sweethearts...I was 15 when we started dating... I don't think all is lost...if you can find an opportunity to talk to him...or get him to respond so you can start talking, be his friend...maybe he will give up the tramp and come home...another thing, my H was totally against anti-depressents...I spoke to his doctor and he was finally able to get my H to try them on a temporary basis...eventually he was convinced that he needed them, probably for the rest of his life...but he has come to terms with that...he feels much better with that cloud of depression lifted of off him...
Like I said...I don't think all is lost...but so many wait for the "movie" return...for the WAS to come crawling back, sorry for all the hurt they have caused, willing to do anything it takes to come home...fact is, that is a fairytale way of thinking...it is usually very quiet...no fan fair...no lightbulb moments...and just wanting to return to their "normal life"... Reach out to him...see if he responds...for some men, especially those who have been crushed in spirit as young ones...they can't face confrontations...they need to know they are wanted...because they have suffered so much rejection they don't want to expose themselves to more of that...
Does this make sense to you???...I think your H is hurting very deeply and needs your compassion, empathy, and unconditional love in order to begin to feel safe and to heal...only then can he stop the need for self medicating with the OW...