Frank, I am so sorry to read this. I understand being "broken" and not being able to give your best. Please forgive yourself this, just as you would forgive someone else in this same spot.
Call me optimistic, but you did say you asked today for a couple more days to get it ready, but that the answer was "no," and that you need to hand it over on Sunday. Looks like you have your "couple of more days," no?
Regardless, please, go easy on yourself. You have beat yourself up enough.
Please find yourself a counselor. Your wife isn't in a place to help you through this anyway. You would be better served getting this all out to an impartial person...