PLC, this is my first time introducing myself to you, but I have been following your situation and I am so sorry you are hurting right now.
I know that there are people who have an IHS for years, but for me, living in the same home as my alien H was one of the hardest points in my journey so far. Rejection when an H is living under the same roof is felt every time you think of him. Which could be every other second, if he is just on the other side of the wall. I felt like there was no moving beyond the pain for me. So be gentle with yourself right now, this is super, super hard.
What can you do to get out of the house and not trigger the pain of rejection? I know that you work and likely you want to come home and unwind, but can you go for a walk with D? Or a socially distanced walk with a friend? Or a 20 minute workout (god bless the endorphins). ANYTHING to get your mind off of the fact that you are living with an alien whom you cannot understand at the moment? I too love to cook and realized that cooking was a trigger for me (H not swanning in and complimenting the smells and subsequent appreciation for the food I made made me depressed). So I stopped for a while.
Whatever it takes for you to feel whole for even a few minutes each evening, do it. You are not alone in your pain.
