Your post reminds me of what my first painting prof told me once:
“The only way to succeed as an artist is to not quit.”
Very much so. I do question my decision of “still not quitting” every now and then. But it becomes less and less of an option as years pass by. In the meantime I witness my friends and colleagues get their “big breaks” early on, while I might not ever get one. But even these thoughts don’t really stop me because I also witness some of those colleagues and friends give up, once things start going slow.
Who knows, I might have already quit if I had experienced a “big break”, but nothing afterwards.