did your state impose restrictions about socializing? maybe you can call the police? that sounds a bit extreme, but if my health was in danger.....I'd consider it. I would recommend taking a picture/journal too when he has his friends over for evidence (and keep a record of all the crazy things he's said to you and behaviors that are out of line).
cardinal, you are not crazy. I know everything must be so hard for you because you are the only one that's experiencing this side of him. I think it's true for most LBSes, outsiders see no difference in our R, but we know what kind of alien our spouses have become.
I mailed my MIL a bouquet of flowers for Mother's Day, and I called and facetimed them with the kids. H went to visit her by himself, and he came up with a believable excuse for me and the kids to not be there with him. Yup, my H does not want to tell his parents about us. He said his mother will go crazy. And for me, I don't need my MIL knowing to validate what I'm going through. whether she knows or not makes little difference to me right now.
I think it goes back to the whole control thing. I think maybe your H has so little in his control right now in his life, he's just holding on to whatever he can. He's still in control of his outward image to his friends and family.
You don't have to maintain any relationship (such as with MIL) if you just can't bring yourself to do it right now. That's me also. I'm doing the bare minimum. Personally I feel bad for my inlaws because they don't even know why they're not seeing me and their grandchildren that much in the last few months (other than because of covid). I know my MIL is not happy about it, but I just can't put her feelings first right now. Ultimately she is H's mother, and I will leave that to him.
Lastly, maybe you should just walk away to another room when your H is on the phone so you can avoid hearing his conversations entirely. Maybe that will help with your sanity?;) stay strong!