Open your own account ASAP. You can do this online with Starling bank in about 15 minutes online. Speak to the bank immediately where you hold any accounts before he clears them out. They can put a note on the account to say you are separating. That way he can't close down the accounts.
Get some legal advice ASAP. If he only needs to stay locally a day a week, he can stay with family/friend or at a hotel. Apply to the CMS ASAP for money for the kids. You can't backdate it and you can do this online.
My ex closed the joint account down without me knowing. I notified the mortgage lender straight away about the separation.i pay half the mortgage to the lender, my ex pays his half straight to the lender. I pay the bills, house insurance and food.
Contact your local council.As a single person you can get a discount on your council tax.
Take copies of any statements, loans savings and any other financial documents you have and keep them safe. He may try and deny finances when this is sorted legally.
If the loans are in your name only then he won't be responsible for paying them.
It's good that you have your parents with you. Sorry you are going through this. Be prepared to be in a rollercoaster of emotion but it will get easier over time.he's not the person you thought he was.
You could invite him to mediation.you can find a mediator online. The government are paying £500 towards this to keep people out of the court.
Be prepared though, some exes can get nasty when it comes to money. My ex did. As a punishment for me not having him back after cheating.