I still of course work extra some times or do productive things in my time off, but yeah unless there's a deadline I'm not gonna worry about some work problem on off hours when I can't even make progress until I get back to my work computer anyways.
Fear/worry/anxiety is the mind killer and often helps nothing.
Relaxing is not overrated at all, it improves your ability to focus, and even makes you more productive. Far from depriving you of any powers or skills.
My experience is that there is not a linear relationship between effort invested and output. It's a diminishing returns problem after 8-10 hours per day, so it's not even productive for me to spend all day and night churning on a work problem, even if I wanted to do that.
I get it now. Sort of.
But the problem doesn't go away.
Relaxing is overrated. It deprives you of powers you have developed or will develop, only to make you a more powerless person.
And a powerless person can never and should never relax.