I worry that this may absolutely drain you guys and that if mom and dad don't make some BIG changes, this could be a situation where they end up living in your house while dad takes years to find a new job. 

That's rough. 

I'd still push them to go to the church. It is what it is for. It's a charitable organization whose sole purpose it to help people like this. And they can be better equiped to help your parents.