Slowly Sinking from Car Payments

 I co-signed for each of my two daughters (college bound) to have a car while they're in college -before my divorce.  Payments were not an issue since he paid a majority of the bills and I bought the food.  Now that I'm on my own, I'm am  going nuts trying to handle all three payments alone.  My ex has finally refinanced the house and I'm expecting my half within two to three weeks I'm told. But until then,  I feel like I'm drowning.  I've called the lenders and explained my situation but they want their money.  One daughter surrender her car without my knowledge and the other got married, followed her husband (military) and left me the car.  I don't want to mess up my credit but it's getting to be to much to handle.  I've tried selling but with no luck.  Any words of advice/wisdom will be welcomed.