Oh, Morgan. I keep coming in just after all hell has broken loose....
You do NOT have to talk to him. He does not have to visit in your house. Make arrangements--maybe at MIL's where he was supposed to be living? Drop them off there, pick them up after he is gone.
Even if he does have to keep coming to the house, you do NOT have to talk to him. I tell you this as someone who had to learn the HARD way--it was too damaging to me to be anywhere in his vicinity, as I kept trying to talk to him like he was still sane, still the man I married all those years ago.
That man is gone for now. We can never be sure for how long, but prepare for forever. It will force you to find strength that you never realized you had.
Remember to call me if you ever want to--you can even wake me up.