"she was abusive. She hit, bit, scratched, pulled hair, and threw toddler like tantrums when she didn't get her way, plus she was emotionally abusive and tore down any bit of self esteem I had. She was an absolute demon."

That so sounded like my Ex from 5 years ago it is not even funny. Thankfully she was not the stalker type she just went on to find another poor soul to chew on.

Dash cam (For Car), Up the security on the house make sure you have 3 inch screws in all the lock plates in the door frames for your dead bolts to your house. Perhaps a security system / cameras for the house might I suggests the subreddit: homedefense they are great for advice on home security systems / camera set up. You need to protect yourself and your job. She seems like the type that could manipulate other men to "White Knight" / attack you. You also need to be worried that she will try to anonymously get you fired I do not know exactly how she would do this but I have heard stories in the past of stalkers doing this to their victims. I do not know what the best course of action is to defend your job because I have never had something on this level happen to me, but I have had someone try to break into my house while I was home so, CCW permit + pistol + Training (last resort of course) Obviously you want to avoid confrontation with her at all costs and document EVERYTHING. Best of luck it sounds like you have a very mentally sick individual on your hands. I am not the end all know all for situations like this so please take in all the advice you can and protect yourself. The best ending for this situation is that she either goes to jail or leaves and you still have your job, your home, your car, and yourself all in one piece.