My ex is being super manipulative and I just don't know what to do anymore. We sold my car when we were together to buy a brand new one when we split I got his old one but now his threatened that his going to ring the police and report the car stolen unless I change child support to a private agreement so he doesn't have to pay. I don't know what to do because I need that money to be able to afford our son's specialist appointments and all his medications but at the same time I need a car to be able to get to all the appointments. He doesn't help with our son even when IV begged him and I'm just beyond exhausted and at breaking point now. What do I do?