I've recently had the pleasure of speaking with Linda Cheung about self doubt.

Here is her summary of our conversation:

A thousand changes but ready for each one.
In this episode of Overcoming Self Doubt Bruno Pešec shares how the discipline of martial arts has given him the confidence to transition industries, find his voice, and speak on failure.  
When asked how he does so much martial arts training - “It’s easy, pack a backpack and pick it up. You don’t need to think about it. Go train.”
Are you overthinking? Worried you don't have the right things to pack?
Clients often tell me they don't feel "qualified" - In Episode 2 Colonel Simon Browne OBE talks though experience as knowledge and handling unknowns with what appears to be intuition; in Episode 6 Helen Williams shares the benefits of a sounding board and getting external advisors.
Don’t let #selfdoubt prevent you from moving forward. Take action. Get data and experience. Incorporate lessons learned. Repeat!
I know Bruno because he co-created Playing Lean which we use during Intrapreneur Nation's Intrapreneurship Mastery programme - so thank you Bruno for this interview, and for creating a game our delegates always enjoy!
Bruno and other high achievers are joining me to explore self-doubt to help others through theirs.
For more interviews and background on the series: https://bit.ly/2YUs5Pt

You can watch the interview here:

Besides watching inspiring stories at Linda's channel, I can also suggest Fearless Leadership by Alan Weiss,  Learned Optimism by Martin E. P. Seligman, and The Six Pillars of Self-Esteem by Nathaniel Branden.

Be mindful of the Dunning-Kruger effect – the more you know, the less confident you'll be, and vice versa. Just because you have encountered vocal opposition does not necessarily mean you are wrong and you should yield. Sometimes the most vocal are those that know the least.

Trust yourself and take thoughtful action.