Hi HesAble-- I just posted on KG's thread that what doesn't kill us makes us stronger-- imagine how f-ing strong we are going to be on the back side of all of this!!
You are going through a ridiculous situation and are handling it with immense strength and composure. When you look back at this time years from now, no matter what happens, you will be proud of yourself and how you took care of your kids and your family even when your H went bonkers. (That is one of the drivers for me... what do I want to remember about myself and my own behavior years down the line?)
Here's another suggestion-- in terms of taking back your space-- are there things you can do physically to reclaim your space? something I did after the first BD is I got all new bedding for the MB, stuff *I* liked and had wanted for some time but knew he didn't really like. If he's not going to participate, do what you want in your own house. Use the DVR for your own stuff. Reorganize your kitchen to make sense for how you use it, not him. (I also gave away all my sports shirts from his teams, which might have been petty, but felt really good and I know it stung him.)
Also, I second Wooba's rec to have the upbeat/fun you show through when you're actually feeling it with your kids. Otherwise I think polite is fine. I think I was actually too focused on my H earlier on-- he said he saw me walking on eggshells and trying to keep him happy, which I think didn't help him to respect me. Now I'm happy when I feel happy and polite but distant when I don't, and can have fun with the kids and his parents when he's there but when they go to bed I close up shop. Mostly because that is how I feel, but also (more than I probably want to admit) I think it demonstrates to him that I am a fun and happy person but that I don't need him to be that way.
Me (46) H (42) M:14 T:18, D9 & D11 4/19 - 12/19: series of escalating BDs 9/20 - present: R and piecing