"I wouldn't file for D unless I was 100% sure about D which you don't sound; it's a difficult and painless (and $$$) process."
I agree with Karen & others on this, there have been quite a few on these boards that have pushed thru on the D only to regret it later. (Which may seem a contradiction to my recent post that I said I was ready to proceed, except I'm going to let him actually take the steps).
"He doesn't seem happy? Why not? Is it just when I have the limited contact with him? Is it me and his feelings of guilt, remorse, regret?
I want more information... against the dbing code. I want to talk to him, put the cards on the table, get it all out."
Pushing for more information will probably lead you to a place you don't want to go. He's probably not happy & feelings of guilt & regret may be aimed at the OW, who he's told is "the one", & may not be any longer.
"Getting it all out" has a big price tag that can result in no useful information. All cheaters lie, as Puppy Dog so often reminds us.
Most A's do run out of steam as a matter of course. While this is incredibly painful at this point, remember that thing's can & do change, & the more you keep out of the line of fire the better.
I'm sorry it's been a difficult day. Do anything you can to take the focus off him. It will help & get easier everyday.