Self Doubt and Repetitive Thoughts with no solution

I am transitioning to a new position and I keep having the same set of doubts and thoughts after every single work day. It can be any circumstance that can trigger these thoughts.
C- After work shift
T-I should know how to handle these situations and make decisions like the other people I work with, who always seem to have it all together.
F- Severe self doubt
A- Buffer with either food or screen time without going to bed or going deep into these thoughts
R- I make no progress with dealing with these thoughts.
I recognise that “should” in the T- line is always unhelpful. But how do I justify it in the context of work requirements? I want to get to a place where I am able to see my real deficiencies in skill set and work to improve these skills without a)beating myself up or b) the other extreme that I become ok with my deficiencies and not work on them. Not sure if this is clear but I struggle a lot with delineating self acceptance from passivity. Also when does one decide that they are “unfit” for a position and give it up completely vs keep growing into the position and adding more knowledge and skills? As is obvious Im having some serios self doubt today! Thanks for the help.