Nero - this is just my 2 cents but I do think that the older MLCer is more complicated in many cases. I am happy for TVS' situation and her courage in having the talk, but I am clear that my xh would choose OW (either one!) over me any time.
It is a talk you only have imho, if you at least have an inkling that it might go well!
If you think about it, the older MLCer has been holding it together for longer, and very likely, it is going to take longer to resolve those issues.
We are deeply a part of who they are, but that is what they are rejecting.
It is very very tough, and some of them work through it and some don't. Your MLCer seems fond of you still which I see as positive. He says affirming things. I haven't had a kind word form my xh in over 8 years. And I do not think I was really that bad as a wife!
It is draining and not very life affirming at any age, but when you are older it can really whack the self esteem.
I don't think your sitch is hopeless at all, but I do think you need to really try and detach as much as you can. Hard, but a life saver in the end.