what if you developed a few bad heuristics about how other successful people were not inherently more successful but just got lucky (or some other external granting of success) as they went along; whereas your hard-earned successes were due to successful personal skills... Hard earned, personally achieved success.

its probably possible to see a therapist about it; but I would suggest you can work your own way around it (consider it a challenge that can be overcome with the correct growth mindset)