I know you are worried about the money aspect, but honestly, don't. First thing to do as soon as you leave him is to apply for tax credits - based on the 12k you said you earned you will get working tax credit, child tax credit and money towards childcare costs. You may also get legal aid because the dispute will be with your husband and so his income isn't counted, but if you jointly own the house then that will be taken into consideration as capital and might have an impact depending on it's vale.
Honestly, you NEED to leave this man. You will be fine money wise.
I would also insist that the house is sold - or let him buy you either way you don't want tied to it - and make sure you tell the CSA that you have separated - him getting that letter will be a nice surprise.
I know you said you don't really care about the money, but set your pride aside and take it.
I would also get the house valued so you know where you stand with that. and make a complete list of all the things you co-own - furniture, appliances, cars etc. Get copies of all your bank statements and have them to hand.
Keep a record of all that he does - and keep things like those fucking lists he makes and take them with you.
Honestly, I would go about it very calmly. Stop looking after him. Stop cleaning up after him. Stop cooking for him and start to pack your things. Be ready.
Start to look for somewhere else to live, even if it's on a small flat on a short term lease, you just need to be out of that house.
It's time to rebuild your life. And think of your kids - do you honestly want them growing up thinking that it's acceptable to let someone treat you like that?
And those calls to your work need to stop - firstly talk to your boss and explain the situation, that you are leaving him. The majority of employers are surprisingly sympathetic to things like this - especially when it's out of your control. Which is why you then need to speak to your solicitor who will write to his solicitor asking that contact in this way stop. If that doesn't work your solicitor will help you get a court order which will detail exactly how and when contact is permitted regarding both you and the children.
But most of all, through it all yuo must be calm. No scenes, no drama, no shouting. Just be calm and level headed at all times.
And good luck. Please, please take the advise of everyone here who is telling you to get out.