Nutts, sorry you're here bud. You'll find that your situation is not unique, but know that you are also not alone. There's some comfort to be had in both of those statements, as weird as that sounds.
My situation is similar to yours. You need to steel yourself, bc if the PA is driving her behavior it'll get worse and more painful for you. You need to start focusing on you, even more than you already have. Exercise and sleep are your best friends. You'll be at your weakest when your body isn't active and you are tired. That's when you get the larger emotional swings and you don't want that.
We are here for you bud. Keep your level head and be strong. Keep posting and you'll get some good advice.
Me39 M11 : T13 D9 BD 5/31/16 In House S until 6/21/17 Divorced 10/5/18