Nothing wrong with focusing on work, especially if you're an entrepreneur or very ambitious. I respect that.
But I think most of us are just putting our eight hours in and then doing other stuff, and that's okay too. The problem I see in the US is that the latter group of people is subconsciously guilty about this and thus spends their free time reading about how to be better at work. It's yet another manifestation if the "temporarily embarrassed millionaire" culture.
How about reading or learning about something that has nothing to do with your day to day job that you find interesting?
EDIT: I was brought up in ex-USSR country, place not quite known for work ethic.
When you accept all this stuff into your world, it is for enrichment. So is playing sports with friends who having a cup of tea and catching up with someone.
I have found that my guilt over not keeping up went away entirely when I switched to this. I don't have an obligation to this stuff. It has an obligation to me for giving it rent-free space in my head.
You're not alone. This is why therapy and coaching are a thing. It's not quite the same thing, but having someone to reflect with you and help you lay things out is useful.
Anything that helps you feel relaxed and at ease.
I'm always super busy with work and side projects, but last December I went to Maui for 2 weeks and it was the best thing I did for myself: when I returned, all the things I had to do ("work") crept back in and I realized what it actually meant to be relaxed (because in this condition, I'm definitely anything but that).