I was in a similar situation when our megacorp employer axed pur project, but without making it official or reassigning us to something else.

The problem isn't that we had nothing to do, but that we had to pretend to do something. We couldn't just stay home. We had to show up every day and waste 8 hours at our desk before going home.

I remember the feeling of numbness when I left the office. I had scrolled through the entire internet, and it took an hour or two for my brain to reconnect to my body.

Nowadays I often have nothing (urgent) to do, but being self-employed, I can just hop on my bike and go do fun things without any pretense of productivity. That's actually quite enjoyable. I could do it all day long.