@SisterNight as all the PP's have said do not leave the property.
Get in touch with your Landlord and tell them that you and your H are separating and that you will need to transfer the tenancy into your sole name shortly.
Get him to give you the passwords to access your Bank Account then go in and change all the passwords and do not tell him what they are.
Then make a claim immediately for Universal Credit, are you entitled to any disability benefits for your health condition? If so that may make it simpler as you will already be in the system so to speak. You need to let them know that you have just separated and are still living in the house together at this point in time but you are entitled to start your own claim as they will ignore his earnings from this point onwards.
Have a conversation with him, he is no longer your friend or in your corner so don't believe anything he tells you.
Tell him that you have notified the Landlord of the separation and that he will need to make arrangements to find somewhere else to live, give him a month to sort himself out. Also tell him you have made a claim for Universal Credit and you want details of all the house outgoings so that you can budget. These are Council Tax (remember to claim the single persons allowance as soon as he moves out), Gas, Electric, Water, TV Licence. If there are other things such as Sky TV etc then tell him to take that with him and responsibility for the bills when he moves out. If you have joint mobile phone contracts etc, work out how long is left on the contract and make sure that you agree what proportion you will pay for your phone only until the contract is up and you can take out your own.
Do not listen to him running you down, your work is unpaid but every single bit as important as his paid work in the running of your family. He doesn't just get to discount everything you have done for years.
Also, be prepared for someone else to be in the sidelines, men rarely split up without having someone to go to.
You will need to Divorce in time but getting him out of the house and separating your finances are the priority for you at this point in time. As he has had control of all of the money do you know about any savings or investments or his pension statement? If so try and get copies of Bank Statements, paperwork with numbers on it etc.
When he has moved out you will need to apply for Child Maintenance for the DC's. Do the calculation to work out how much he will need to pay and then if he doesn't agree to that sum then make your application to them as soon as possible as I don't believe they can backdate the claim.