How to claim alimony and children maintenance from husband without divorce

Hi.

My husband refuses to give me the rights of a wife and does not want to divorce either. He sent me to my home country 2 years back and sends minimal maintenance.

I have 3 kids who are not going to school. I want to come back on a visit visa, and he says if I do, he will leave the house and not renew my visa or pay any expenses.

What should I do?