The self-doubt is horrible, but not nearly as bad as that dark, desolate, hopeless road you go down when you contemplate that self-doubt.
The self-doubt is either a hindrance and something to overcome in order to move ahead in life, or it’s a form of self-preservation, something deep within that knows the truth, something saying “No, you’re a fool and incapable of doing this or being that; stop while you’re ahead.”
Thinking about that self-doubt, wondering if it’s right, casts every interaction, everything thing I’ve done, into the “question reality” box and pretty much gets stuck there.
Ultimately, there’s no way to really know because no matter how much I weigh accomplishments/failures and any other “fact” I can use (comments, comparisons, etc., pretty much anything that can give me pieces of the reality puzzle), my mind throws a big, “but…” at it, and I still fall short. Analyzing is supposed to solve problems, but in this case, it just makes it worse.