And no me jumping on him doesn't help the sitch at all. But dambit don't I have a right to stand up for what is right? At least how I will allow myself to be treated?
Of COURSE you should stand up for how you are being treated! That is why you aren't having sex with him anymore. That's why you aren't allowing him to physically harm you. That is why you have healed yourself enough to see that threats/violence against them (H and OW) only hurt you. That's why you have made your own decisions and done your own thing with painting.
Unless OW shows up at your house or around your kids, she is nothing to you.
Of course, you can file. That would end his adultery. He wouldn't be cheating on you anymore. But you don't want that, so you will HAVE to wait it out, let it be, and set boundaries to stay peaceful.