I always thought "impostor syndrome" was where in my current position I am just pretending and not really qualified to be in. What you are describing is about

I always thought "impostor syndrome" was where in my current position I am just pretending and not really qualified to be in. What you are describing is about overall worthlessness. For impostor syndrome, I tell my staff staff the following. I approach it by letting my emotions be driven by my logic. I look at goals I have set and see if I achieved some (or most if I am a perfectionist) of them. If so, my emotion is wrong. If I failed all of them, then likely it is not a syndrome and I need improvement. The liar will try to deprecate the delivery (e.g., was not good enough, not exact, was just partial), but the logical part will be able to use facts. It is conscious work to recognize the negative inner monologue and snip it off early on with fact. with time, it can become a second nature. The flip side of it is the Dunning–Kruger effect, where one things they know everything, even through they are oblivious. Much harder to deal with it.