I fear for you because your stbxw is irrational in such way that seems to be escalating.
It's must be scary to see someone that close to you change into some one you don't even know let alone want to know.
Last year a ww and her lover conspired to frame the bh, a teacher by planting a gun and pot in his car, making a call to the cops, to tip them off. http://glennsacks.com/blog/?p=2352