Chris I feel your pain. I was a stay at home mom on and off during my marriage. We have small two boys. I wasn't working when I finally had enough of my ex's behavior. I finally got the guts to tell him to move out. The house was in his name, he made the payments but I told him to go live with his mother. Check the laws in your state. Because he purchased the home during our marriage, half of it is legally mine. I didn't worry about the payments, the loan was in his name as well. He got mad of course, thought that he could come to the house any time he wanted, threatened to quit paying the bills. He even went to see a lawyer about it. This man went so far as to shut off the phone, electric, and started switching bills into my name. Well long story short, I got a lawyer. My ex will have to pay for all of his stupidity in the end. He is in a s**t load of trouble with the courts for his actions.
My advise. Be smart. Study the laws in your state. Call a lawyer. File for the divorce, file for child support. File for spousal support, if spousal support don't work ask your lawyer about APL (Alimony Pendente Lite) Basically its where your ex has to pay for your attorney fees, because he makes more money than you do at the time of divorce.
And maybe this is mean but before he does it to you, close your joint checking account. My ex did that to me with out my knowledge. I was at the store getting milk, couldn't figure out why I was declined. I knew the balance and yeah it was more than $2.55.
I'm not trying to sound mean really I am not but what men seem to forget is that THEIR children come first. Some times we have to make them see this even if they don't want to. If he wants to pay for his girlfriend to live then he has to pay for his children to. You can't make him...but the state can. It's not much but at least it is something.