Premanand Maharaj Ji
How do I keep doing my duty without brooding over mistakes and results?
Do your duty, leave the result
Do the righteous duty the scriptures lay down as obedience to God, unmoved by pleasure or pain, gain or loss, victory or defeat. Our effort is ours; what comes next is for the Lord.
Do your duty, righteous action as the scriptures prescribe it, simply to obey the command, whether it is completed or not, whether it brings pleasure or pain.