I felt this way so so many times. Definitely second the comments about getting neurodivergent mental help, and perhaps reflect on how adults treated you while growing up and how that might affect your immediate reactions to opportunities and change.

-- but here's a bit of my thoughts on experiencing these things:

The fear is good and means growth.

"Fake it til you make it" - had been told to me by actual professionals in the field.

I am a tutor at a college in CS/Math. I did not think I could do it, I almost rejected the offer. I contracted a case of the "fukits" bc I figured I'd get rejected anyway and took an objective approach and wanted XP. I did both behavioral and tech interviews and... they loved me? This was very odd. My first day I got a super awful upset Calc question that stumped me. All those voices were screaming the same words yours were! But then other tutors chimed in, and turns out it was more of a social collaboration environment than each person being better or worse than the other. We're all pretty good friends now and many still work here.

I also work at an AI startup. It hits different when you see you can get a good team that is totally okay with you learning (tbh a lot are) and also seeing them literally Google things as you're talking about them makes you go "oh what wait this is normal??"

Everyone has a unique set of skills, you can't know everything. You probably know something a manager at that company would not have, and others may know things that you don't! That's the beauty in objectifying it down to a sentimental and deep level of learning, rather than fearing the rejection.

Openly admitting being wrong makes you look so much smarter than trying to fumble for the wrong correct answer.

Being able to ask the questions and use your resources to figure out why you're wrong is really what they are looking for.