Premanand Maharaj Ji
How do I deal with failure?
Right to action, not to the fruit
Bhagwan's command is that you have a right to your action but not to its fruit, so do your duty and leave the result to him. The lesson is that fixing the result in advance is what brings disappointment and worry.
That is why Bhagwan said karmanye vadhikaraste ma phaleshu kadachana: you have a right to action, not to its fruit. You only do the action.