I can’t say for certain where it’s from either, but the longer version is now very popular in certain outdoor groups and at US National Parks:
“Take nothing but pictures, leave nothing but footprints.”
Apparently one researcher was able to trace it back to a newspaper article from 1954 about Bandelier National Monument (an amazing spot in Utah).
https://quoteinvestigator.com/2023/05/30/footprints/
And I agree that it has many crucial implications today. We should doing more to live in harmony with nature. We are part of it, no matter how much our concrete jungles try to seem otherwise.
I absolutely hate being sick and can spiral downward after it too. What helps me is to do my best to focus on the small wins.
Am I feeling better than I was at the worst? Great! Did I get out for at least some exercise? Great, do more tomorrow.
It’s also good you’re identifying the habits you want to avoid, like YouTube and social media overload. Now just try to replace your time on them with something else, almost anything else. Even just dedicating time to one movie or trying to read a few pages or a book can snowball the direction you want to go.
You’ve got this. You’re not hospitalized or worse from your recent illness. And it sounds like you’re on your way to recovering, even if it’s going slowly. One step at a time.