Even when you have doubts, take that step. Take chances. Mistakes are never a failure - they can be turned into wisdom.
FAILURE, MISTAKES ARE NEVER A FAILURE
Failure seldom stops you. What stops you is the fear of failure.
FAILURE, FAILURE SELDOM STOPS YOU
I think that failure by your own standards is certainly a form of success.
FAILURE, CERTAINLY A FORM OF SUCCESS
Success represents the 1% of your work which results from the 99% that is called failure.