I don't think its possible to be working on 'absolutely nothing'. I think you'll find that if you really explore this idea that you can almost always go further. For example. Do you clean your house? Maintenance is something. The status quo is something and it need to be maintained to exist. I think you recognize this because you admit that you're working on yourself.

The only time I think you could truly do nothing is when you've passed.

I would say I was in a similar place - Wake up, Go to work, come home, watch youtube, sleep, repeat; I had projects I was interested in but couldn't bring myself to do them. For me, part of the answer was changing my environment, the people I was with, the culture was to chill because you're exhausted from work. Another part was, like you're doing now, working on yourself. Another, specific part of working on myself was taking inventory of the things I 'valued'. Did I truly still value those things or were they things from my youth that I am clinging to? Do I value them because I authentically value them or is it because culturally they are valued? Am I applying those cultural valued to places that matter to me. For example: "Hard work". I do value hard work, but the places I was applying that value did not provide return on the investment. So now I apply 'hard work' elsewhere.

I think it is both necessary and good to do this from time to time. Good luck on this journey.