Very sorry you've gotten to this place but Cadet is right, your old marriage is over and there's not much you can do unilaterally to change that when faced with a deadline.
First of all, you don't have to do this on his schedule, but if he feels you're just delaying, he'll get anxious and pressure you, so if you need a break, just propose an alternate schedule -- "H, I understand you want to sit down and review this, but I'm a bit overwhelmed right now. Let's agree to discuss it on 9/20, 2 weeks from today. That will give me time to mentally prepare."
Hi MP, sorry you find yourself here, but you are in a good place. You'll get lots of support and info on here.
Accuray is right - tell him you still need time to sort your mind and emotions out. Give your H a date that you will sit down and discuss it with him. Accuray's words are perfect.
Stay strong, and remember you're not alone.
Both 50 S14 M 16 yrs (his 3rd; my 1st)
ILYBINILWY - 24 Dec 2012 H moved out - 27 Jun 2013 Legally separated - 6 Sep 2013 Closing the door and changing the locks