I am glad this works for you! Maybe it's because I can't switch my mind so easily, I prefer a physical distance (I don't think a separate room would be enough for me either).
What worked for me best during lockdown was strong ritualized schedule (which is completely at odds with my normal personality).
What used to be going to work in the morning became exercise. Then, when it was end of day, we went outside. I have kids which made it making more sense. But you can go outside for walk or read book outside etc. The point is that you leave room and do something that causes mental switch.
To be fair I've been working 60% remote for a few years now, so moving to 100% wasn't a huge strain for me. It's actually something I've wanted for a while.
I've had time to get my head around the separation you talk about, I guess. Also helps that I'm on a small team and we all slack something like "Signing off now, catch you tomorrow" at around 5.30. Puts an end on the day.
If you don't have a separate room, it's hard to see how much difference it can make. I've worked from home since 2008 with a one-year break immediately before COVID-19, and I'm glad to be back, but the separate room was essential for me.
