Maybe it would help to post your budget in F&F. If you aren't paying rent or a car payment, and only have 7k in cc debt, and no student loans, it's hard to know where exactly your money goes every month. The posters over there know a lot, and could help you formulate a plan to truly exit, including paying your MIL back for rent.
We were young parents, too. 20/21 when our first was born. DH made $7 an hour and yet we were able to pay our own rent in a small apartment and then a small 2-bedroom house when our youngest was a baby. He did get a new job once I was a SAHM making a whopping $11 an hour and our rent at the time was $850. We didn't have food stamps or otherwise, so I guess I just feel like there HAS to be a way you two can support your family without being stuck in MIL's crappy place and borrowing a vechicle - even if your DH only makes min. wage. Your debt can wait; nothing is going to happen if you stop paying the CC's except collection agencies harassing you. Seriously, to me that would be worth living in a safe environment away from toxic IL's. I just wonder if most of your money is truly going to debt and if it would even make a difference in whether or not you could afford to move out.