Tate. Even I can see, with my newbie eyes, that you need to get this sorted. What is wrong about what is going on? An affair (multiple?), your BIL..... You need to show her you are not going to stand for this. What do YOU not want to put up with anymore? Deliver it for you (and your kids).
On the job front. Ignore her. What would you do if you were happily married right now. Get another job with a good package? Then do that. Don't sit at home wallowing. When in the eye of the storm I moved to a very good job (from one to another). At the time of my W leaving with the kids I chose redundancy and set up the company I always talked to my W about setting up. Gave me something to focus on (GAL) and earnings are soaring. Happy and independent. What would YOU want to happen for YOU? Deliver it for you (and your kids).
M46/W40/D8/S6/T20/M12/Separated 6/2016,W takes kids Issues2009 Wpartying w/g.f's2013on EA2013PAdeniedWleavesMBR ImeetAP/EAhalts VariousBDDates MFCourse WSpew EAresumes I halt Wrages DBIng4/2016