Not doctors, but another very high-pressure professional environment that has similar egos and personalities.
In my professional environment, I've learned that 90% of being respected is projecting confidence, intelligence, and competence: conveying through tone and body language, "I know what I'm doing." Most people naturally respond with, "Great, let me follow your lead" or "Great, I trust you to get the job done." I taught myself to do this even when I don't feel
confident and become adept at concealing that.
Fortunately, humans are more easily fooled than dogs about the lack of confidence.
If you can "play act" professional confidence well, most people still react to you as though you are know what you are doing, in my experience. Try to play a role -- the character being the well-respected doctor you want to be. Eventually, you'll likely take on that role for real.
If you want to second-guess yourself, just don't tell
people you are doing it. For example, you can go through and double-check matters and tell colleagues it is your own personal routine for ensuring accuracy--"this is what I always do because I'm careful." If you catch an error, fix it, because that's what good professionals do. Period.
Ask the "dumb question" in your head before saying it out loud--pause, think, realize you can answer it yourself, then move on. You can likely even privately verify that answer in a treatise or online resource, if you want a double-check.