I quite enjoyed this!
I find that I can sometimes get past these sorts of feelings by relentlessly publishing/writing/producing whatever is in my head right at that moment, even if I don’t think it’s good. Sometimes it is a personal delight where I’m writing something for myself, but more often than not the self-doubt keeps telling me it’s dumb. But I push on anyway because there’s a strange accomplishment and satisfaction within that.
The drive to overcome to the self-doubt becomes the reason, not just the creativity. It’s the one thing I like about NaNoWriMo. The writing goal is just challenging enough that it forces you to remove doubt and just type away.
Even though fast creativity usually isn’t “good” creativity, sometimes it’s the exact sort that I personally need. Heck, I was tempted to delete even this reply three times while writing it. Killing that self-doubt by clicking publish always feels better than deleting words, even if I don’t end up totally loving the thing I made.