We all should learn from our fails, but when we chose to doubt, we will never know what could've happened.
I always doubt myself, not being confident enough.
Life is tough, we can't make ourselves to perfect every time just to please someone else.
They all made us doubt, but we should be strong enough to able to handle criticise, no matter you did something right or wrong, just listen to them, learn something from it, come back as a stronger you.
Work hard in silence, someday your hard work will pay off.