My in-house separation was brief, thankfully, but it was still the hardest part of the whole process. Especially since he was going on dates with OW each evening, and then coming "home" to me. Gag.
Two things that helped me the most:
1- claiming my OWN space in the house and making it absolutely off limits to him. In my case it was the master bedroom. He was already sleeping on the couch... so one day while he was at work I moved every single thing of his OUT of the master bedroom and down into his son's closet/room. Not one thing of his remained in the room and he had no excuse to enter. At night I kept the door closed and locked. All his bathroom items went into his son's bath as well, and they had to share for the remainder of his time here. I can't tell you how much better I felt once I did this.
And 2- I tried to view him (and his difficult teen son, whom I had to give up all pretense of trying to parent since XWH would no longer allow it) as out-of-town guests who were staying with me and would soon be leaving. Like distant family... whom I didn't know very well. This enabled me to manage daily "courtesy" but helped me stay a little more detached. I stopped concerning myself with their comings and goings, and tried to view it as their business was their business and mine was mine, and we were just sharing these accommodations temporarily.
In-house sucks... no way around it. I'm glad yours will be over soon. Hang in there!! HUGS! Me: Enjoying life
Him: Someone else's problem
Rock bottom became the solid foundation on which I rebuilt my life. ~ JK Rowling