OK, you COULD go to a class she's holding and humiliate her in public... just speak calmly and loudly asking her to stay away from your husband, etc...
You have to weigh that carefully, but I am putting it out there...
SHE will be LIVID, but the idea that she could lose her job if she keeps interloping may scare her off to a degree....
I am going to reccomend that you keep living in the same home with him.. It's your home and you leaving will to your H and OW validate their affair as acceptable to you...
If YOU stay living there and your H doens't move OUT, the OW will start harassing your H to do something about it and that will turn him off of her very likely.
The crap about your H not being in love with you etc is BS if he's having sex with you.. we have ALL HEARD that nonsense..
If those are the only complaints he has then he's just having an affair and things will be fine after he ends it... Those are classic excuses for people to invent when they are two-timing their spouse.
I don't reccomend you moving out at the moment, I dont think that's going to improve your marriage and it will very likely ENCOURAGE OW to press the affair more.