So sorry to read this, advice.
Don't know if this has been pointed out before, but could it be that your H has cajoled you into giving up your job purely out of cruelty so that you are totally dependant on him? I know it sounds awful but I'm a cynical bitch and there's really very little that would surprise me when it comes to deviousness.
You do have his address at work, right? Do you know his coworkers, his boss?
Where I'm from the authorities will take money from your payroll if you fail to give them your new address and contact details. You should see a lawyer ASAP, armed with all policies, insurances, bank statements, etc. Have you opened a new bank account in your sole name and put the kids tax credits into it? IME you should also let your bank manager and others in the bank know, what's going on and freeze all cheque books, etc. just in case he rides off into the sunset leaving you and your dc behind.
One word on the side sweets, dust yourself off, go to your previous employer and explain the situation. Make it lunch or coffee and tell them you were duped, sorry and would appreciate coming back. In my circle of friends and colleagues this is quite common, if you had good ties with them, why not explain and go back. Don't let it go and don't waste time girl. Go for it!!!