I am very sad that this happening. Well done you for being so brave.
I am also very angry on your behalf. You say he is in thousands of pounds worth of debt. If it was me and as a matter of urgency and short term i would syphon another 2-3 grand from his account so would accrue the debts to get me and the kids out. Of course it is only possible if you have access to his accounts. I d rent a small place near my family and call CAB. I would not give him any new address. Then look for a job stacking shelves even. You say your family cant help you financially but could they help with childcare?
I might be totally naive but you need to get out quickly and start re building your life.