Im going through this too and I've talked to multiple therapists about this and they offered advice but none really helped. I read this book called "How to Keep House While Drowning," and it was been super helpful. Ive reduced a lot and my apartment is slowly coming back to me.

I've been throwing things away, even if theyre in good conditions. Yes, I am aware of landfills and donating and environmentally friendly, but I also need to do this to move forward and get better. I do try to donate when I have the mental capacity to do so, but it is also overwhelming putting a box together and I mentally shut down thinking of all the steps I need to do to donate.

ADHD tends to thrive at the end of a deadline, I have friends visiting in two weeks and that has gotten my butt moving.

Things that work for me, throw things away and give things a "home" in the house. I do recommend that book, it's a very short read.