Hi FHS, hope you're out enjoying a great bike ride!
MLC sucks. Your H seems to be getting the pickings of both worlds as he chooses. As your H continues to move in with OW remember that it could be the best thing to happen. Many times once they have to put up with each day to day the infatuation quickly deteriates. You will begin looking better and better!
I also wonder, what are you doing to protect yourself financially and 'remove' H from your life? It is a very fine line to walk and can be very risky, but how do you think your H would react if you had some things packed up for him? Basically, do something different.
I too have joint business ventures with my H, it was difficult to keep all the balls in the air during all of this mess. H would be angry if I didn't do it, he would be angry if I did it on my own, basically I didn't do anything right in his book but I had to do what I could to make everything run with or without him.
Keep taking care of you.
Live your life while you are still living. Riding the trail less traveled.