I agree w/DnJ...do not share anything w/your h in the way of what you are attempting to do w/the settlement.
I have one question...why don't you take half of what is in the bank account and let him have the other half? I would be very transparent w/the paperwork once you have done this w/his lawyer...not him. He wants access to the account, then give him his share and let him have all the access to his portion of the account.
As for the children, I can't see this man being accountable and responsible for their daily care.
If you should ask your father for assistance, be sure you not tell him or his lawyer at the moment where the support has come from. He's already made up a story that your father has been supporting you.
Come here before you do anything and bounce your ideas off of us.
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.