i don’t know

hi there
i started a new job and I’ve noticed how I insecure i actually am.
I’m ashamed and almost scared when i don’t know things that I already learned in school. And try to hide my non existent knowledge and i feel ashamed. And i am scared because if they find out how not smart I am they will not take my seriously and think i’m not suited for this job.

I know this comes from my childhood experience.
i’m the kid that doens’t aks anything because i’m to scared of the reaction of others. If they would say stuff like: what how do you not know that???

i’m even to scared to take on work from my boss and deliever the result to him. especially when he’s watching me. Even simple stuff like searching smth on google.

thanks for your help.