There are many social welfare services that can help you. The courts should be on your side.
What are the ages of your children? Even if your ex-husband is a screw up, he
IS responsible for his children. If he is working, get the courts to garnish his salary.
There is no reason you and your children should be subjected to this abuse.
Have you considered getting a job??? while your children are in school or daycare???
Before considering selling your furbaby, maybe you can sell your car?
I wish you luck ...