I would most certainly ask again and tell him that you can't pay him until you've received the support money. That you are in the hole in all areas of your life because you have been trying to pay child expenses on your salary and that your spouse hasn't coughed up his share of the child expenses for D12.
If he says he doesn't know, then tell him to find out. He should have some idea by now as to when you can expect some money to help support your child.
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.
