I was kind of the same, very shy to ask questions and "look like a fool".
That was until I got my PhD. I still realize that I don't know jack shit, but for some reason now I don't care, I now feel I don't have anything to prove to anyone. So, if I don't know something I just ask. Do you think I am stupid? that's your problem, not mine.
Hopefully you don't need a PhD to realize that like I did.
I am in a similar situation. I once explained to my dad that having a Phd has allowed me to proudly proclaim that I don't know something without any pressure whatsoever. Not that you need a PhD to say I don't know but it helps.
Oh, I'm not shy. Far from it. I just am politically savvy enough to know that saying anything outside of what is expected just opens you up to attack. It's an impossible game to win.
That was until I got my PhD. I still realize that I don't know jack shit, but for some reason now I don't care, I now feel I don't have anything to prove to anyone. So, if I don't know something I just ask. Do you think I am stupid? that's your problem, not mine.
Hopefully you don't need a PhD to realize that like I did.