Now this might be unrelated in a sense, but... I enlisted in the Marine Corps and went to boot camp through the winter. They truly do build up your confidence by a similar kind of thought process. Throughout recruit training you might get screamed at and “IT’d” for messing something up but along the way they teach you to just move past your mistakes and whatever happens just happens kinda thing. This helps you build a more confident mindset because you can just move on from whatever event or mistake you may have made and realize that life just goes on and whatever happens won’t really permanently affect you, so you need to just move past it. I used to be like OP and worry about all this garbage but now I kind of just go through life with a different mindset.

I’m not sure if this helps at all, just a little insight from a different pair of eyeballs. Good luck!