"I'm not better than everyone else but I think I should be" is not impostor syndrome. You don't see yourself as an impostor, wanting to push yourself hard to achieve more is not impostor syndrome.
If you ran a very popular blog and still felt you couldn't write blog posts then that would be impostor syndrome. If you had published a lot of papers and still felt you couldn't make something noteworthy then that would be impostor syndrome. But feeling bad over not being able to do those things when you haven't done them then that isn't impostor syndrome at all.
Be kind to yourself :)
FWIW, I struggle to relate to "competers". I do things because they make me fulfilled (or put food on the table), not to "win" or be the best at something. I don't think it's something everyone can relate to.
This is definitely not true.
To each his own, the imporant piece in my opinion is to not judge others by your own measuring stick or live your life trying to measure up to others to get their acceptance or approval.
Every runner practices and runs to win the race. Every fighter also fights to win a championship. I realize a job isn't any of those but when you realize that ultimately a runner and a fighter both run and fight against themsleves, to be the best they can be and nothing more then maybe that is something we can all relate with.