There are attorneys who who donate their time in cases like this, although you may have to wait until one if free, to handle a divorce. You can still talk to them regarding your rights. My father told my mother many of the same things.
Once she was finally able to break away and talked to an attorney, he told her that because of the number of years they were married, she had rights to part of everything he had - even a future inheritance he would get when his mother died would be part hers.
My father hanged his tune when he consulted with his attorney and was told the same thing. He didn't mind losing his wife, but having to give her half of everything was another matter.
You can also usually get him to cover some type of education so you can support yourself and the children, and a temporary alimony. He will have to support the kids too, until they turn 18. When you get out, take a financial course; start reading up on it now on the internet. It will help you greatly, in the long run; letting bills go unpaid and leasing an auto are not great financial decisions.
Also, we've lived for years on less than your husband brings home weekly as our total monthly income. You should be able to get by. Unless you have outstanding bills, he is doing something else with the money.