Is there a term for the fear of being stupid?

I think “Imposter Syndrome” would come close but I don’t know that it quite fits the bill. Having an imposture syndrome would, as I understand it, have the prerequisite of success, and feelings that this success was undeserved.

My fear is that I’m stupid but I don’t realise it and I’m going to be exposed to myself an others. It’s the reason I don’t raise my hands in meetings and I don’t ask certain questions.

I’m English and living in America and people often assume I’m going to be highly educated but I only have a high school education and I’m from a working class background. (I suppose this might qualify as imposter syndrome)

It goes beyond that though. I’m trying to write a book and often I’ll ask myself, “who am I to write a book? It’ll probably be filled with cliches and spelling errors.”

Also, I struggle to learn things when people explain it to me. I’m far better at learning on my own when I can stop and think things through. I like to know a thing inside and out. (Even with that small justification I fee as though I’m trying to prove to you I’m not stupid.)

Anyway... I’ve banged on for a long time now. Is there a disorder or syndrome that matches the one I’ve described here?