golf mom, It appears that he is dragging his feet a bit. They scream and stomp their feet for a divorce, and yet, many will drag their feet until we do the final bit of work to just get it over and done with.
Or....
He could very well have forgotten about it...their brains do tend to turn to mush during mlc.
Or...
He is pulling a passive aggressive act on you since you stated that once the retainer is paid, you'll have minimal contact w/him. PA folks can be pretty manipulative and controlling in a very subtle way.
Whatever is going on, please do not "expect" him to do anything. Your expectations will have to be zero at all times. Unfortunately, you can't rely on them for anything, i.e., they say they will do something and it may or may not get done, the same will apply to finances and that's why it is so important to watch the bank and credit card statements.
I would try contacting him one more time and see what type of response you receive. If you don't hear from him, I would see if my lawyer would be willing to accept a smaller payment up front, but explain what has happened and then work out a payment schedule until you can get your finances in order.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.