Notice your thoughts
Low self-esteem is fueled by self-generating background thinking. Work brings about unexpected issues that private life hasn’t prepared us for. Something as simple as “I can’t do this” pops up, we take it for granted, and behave accordingly. It’s a pattern so subtle that we barely notice it - and we hardly question it, too.
Whenever a “this is going to be hard” or a “the boss will judge me for it” comes up, just observe it. Understand what your inability to do the work is: only a thought.
Don’t fight - just act
Avoid positive thinking. You can’t fight thought with thought. Use action instead.
“Action”, as the opposite of “reaction”, means being proactive. Don’t wait for external requests: challenge yourself, starting with small, work-related things. Work hard on your strengths first.
You’ll build your confidence step by step and end up showing some will to take risks. Not bad for your career.
Say what you think. Be careful not to engage in “uptalk”, the tricky habit of expressing opinions as questions. Don’t say “don’t you think it’s like that?”. Learn to say “It’s like that” and see what happens. Skip any clarifications or excuses. Get to the point. Add details only when asked.
And stop being sorry: you did what you did for a reason. You needed an extra 5 minutes to complete that awesome presentation. Say “Thank you for your patience”, instead.
The final step will be dealing with praise. Learning to accept compliments will testify that you’ve realized just how worthy you are.
And if no one is praising you?
Well, praise yourself and let the good you’ve done be known.