A long time ago something clicked for me and I realized other people have only as much power over you as you grant them, and the main thing standing in the way of your own success is yourself.

IMO/IME confidence comes mostly from realizing that almost all failure modes are, in the grand scheme of things, impermanent and insignificant.

Worry less about what others think, worry less about most consequences, and just attempt whatever interests you. Pay attention to your mistakes and incorporate some learning from them in to your next attempt.