I'm sorry your "conversation" with him went awry, but thats what happens the majority of the time R or D talk spin out of control. Unfortunately, he drives off in a big time huff, and saving the M isn't exactly on the top of his priority list, pushing this D through, probably is.. But whats done is done..so now the focus shifts to what you do from here to stem the tide..
I guess the first thing I'd ask myself is whether it is becoming more painfully obvious by the day that maybe this person isn't the right one to spend the rest of my days with, maybe just maybe I deserve better and so do the kids..
Second, i'd do what usually stops the bleeding and frees him up to think more rationally and that is: Back off of him entirely, let him initiate ALL contact. Everytime you speak with him, you are calm and cool, very confident in yourself. Load up on the PMA. NO MORE R TALK, PERIOD. No more discussing any feelings or anything, as far as he should know, you're DONE and moving on, PERIOD.
In terms of the divorce proceedings, you can use it to your advantage if you merely allow it to go through without causing difficulty. If your aim is to stick it to him for having put you and the kids through this, thats fine, but it will put you at ground zero in his mind in terms of wanting to work things out. If you stall, you become his adversary and he is then armed with more emotional ammunition for wanting to leave you. If you comply, stop the continuance and allow the D to happen, you are showing him that he is free to go if he wants, you're not standing in his way, too bad it didn't work out, but you love him enough to set him free. I don't know about you, but I'd rather him think you are sacrificing your happiness for his by doing the latter, moreso then having him see you as the immovable object standing in the way of his freedom, by purposely dragging out the divorce.
You don't know how things can change two weeks from now or whatever. This guy may be vascillating despite pushing for the D. Your best bet is to lift all the pressure from the sitch, leave him alone, and don't impede the divorce proceedings. Combine that with showing him you've had it and you're moving on with or without him, and you will know what you've got.