Hope your doing ok and feeling a little better?
A man like that is no man at all and you and your children really are better off without him. It'll be hard and you have every right to be hurt and upset but your energy is better spent on keeping healthy and looking after yourself. Go to citizens advice and get their help on what to do about him trying to sell the house and getting him to pay his way through the csa etc. As hard as it is try and be the bigger person, your children will thank you in the future, if you let him have access etc and he chooses not to use it then they will know you did your best and he is a waste of space.
You will be ok and you can do this x