I’ve got ADHD/OCD so I don’t know if this changes things a bit, but I tend to rotate my hyperfixations and a lot of them involve things like going outside and riding a bike, skating, hiking, etc. so I’ve found it to be a good way to break things up. I also keep a bedtime mode set up on my phone where everything turns greyscale and the phone tells me to go to bed. It’s not perfect, but it definitely helps!
GLORY TO YOU AND YOUR CATS!