I would highly recommend the book "Four Thousand Weeks" by Oliver Burkeman. The main theme of it is that many of our anxieties stem from inability to accept our inherent limitations as humans, and that trying to come up with the perfect productivity system / planning / etc. are all coping mechanisms for that angst that only fuel it over time.

As someone who has struggled greatly with these issues, it was an enlightening read.

To loosely quote the book, shifting your perspective doesn't erase the anxiety, but makes it not quite so unbearable.