Sometimes when the sauce begins to boil itself over things start to get very sticky indeed! You are making moves to be rid of him and that is going to get him stirred up. Do what you need to do to be safe, but don't let fear keep you stuck. I imagined all the worst I could get from my EX as I was leaving and took precautions accordingly, but I couldn't let that be my excuse to stay as I was. Fear of something that might happen is far different than fear of something that I already know has happened and will continue to. In my case the verbal abuse and physical threats were real and would only continue. The behavior of his that I imagined was worthy of planning fo on my part but not worth staying and waiting for.
You are at the point where he is going to pull out all the irrational stops and come at you with all he's got. Seems now you are quite the loose lady with all the dirty secrets to bare and he's the town cryer. Poop to that! Have a laugh, cancel FB as you have or whatever other access he has, even send out a random note to friends to expect some written tirades via email from him so they don't worry for your well being and can just delete them. Don't expend your energies though putting out his ridiculous fires. Sounds as if he's making quite a fool of himself and those who know you will see it all as just that.
Get out those ear plugs and do what you can to cut off his contact with you. If that means setting more firm boundaries with his family to limit contact, than you may have to.
I think you're on the right path and doing quite well. You've got more strength than you know. You're just letting worry seep in. Certainly natural.
Hang in there!!
Alice