Y'know what it could be?
I think its cause as you get older, you kind of worry more about getting it right more than
having fun showing off your ideas. Like, you take the criticism to heart and carry it over to your work and you improve..
but you kind of lose the wonder in the process.
Kind of like magic in some way? You find out hows its made and performed and once you learn the tricks, it stops being fun on a personal level
ALTHOUGH, HERE'S A FIX;
..what you need is to see the fun in entertaining people again with your art? Y'know, when you're young
its kind of easy to 'WOW' classmates as that art kid because everyone is doing their thing and looking for distractions
and see your art as super awesome but then they get older and are like' Wow, thats really cool! But I can't hang around for long,
gotta pay the bills!' and your audience kind of evaporates irl and url. No audience to show off your magic.
Might explain why memes are a thing? idk
I think its down to seeing the wonder in the world around you again, and channeling it into your artwork
Maybe you need to go hobo and be a travelling artist with friends or something? Might be an idea, could even do installation art or something to see what you can do with all the art skills you've developed over the years?