J.A.
K., I don't know what the terms of your divorce are. Does he have legal rights to see your son on the weekends, for example? It may be that you can't just pack up and go too far. Legally, and for your sanity sake, you need to know what you actually can do. Here in Grand Rapids, MI, there is a place called "Safe Haven." It is a place for abused women and children to come and either get housing for a limited time while seeking what to do, or just to talk with someone at their office, and start going to classes on how to "rethink" outside of the abuser's control. I've been to these classes and can say that it is really helpful. If you need to talk, please feel free to pm me. I'll send you my phone number as well.
I'm so glad you know you're worth more too. The truth is, damage is being done for your son as well, and the previous comment about this being a terrible example for him is right on target. We learn what we live. I'm definately praying for you and getting through day by day. All the layers of sorrow can't come off in one day, but a good, safe, choice today, and another tomorrow, and the next, will help you invest towards a healthy path, that you can live with. Best of wishes to you.
J.