Draw The Bow
The Bhagavad-Gita tells of a story in which a conversation takes place on a battlefield between The Lord (Krishna) and a young warrior (Arjuna). The warrior is afraid to fight the battle because many of his opponents are relatives who have risen against him. He doesn't want to harm them. The Lord tells him he will not for their bodies may die but their soul/spirit is eternal. He tells this warrior to pick up the bow—meaning—to shoot his arrow.
Arjuna's problem was his taking it too seriously — the weight of one life, one outcome, one identity. Krishna's answer was not "don't take it seriously" but "take it seriously in the correct way": act fully, but release the white knuckle grip on the result. The soul's immortality is what makes this possible — if it's not the only round, the stakes go from existential to playful. This is līlā — "cosmic play". It's real, but not final.
The Hindu believes life is not a one shot deal, but an eternal struggle in lifetime after lifetime as you reincarnate into the next. This is a very old belief going back many thousands of years. The lesson to learn is that you can only try your best, but don't worry about the outcome. You must let go of the need for a certain result and just focus on following your heart in what you have passion for. You must pick up the bow, draw and shoot the arrow. You have an eternity to try. What is important is your courage to keep trying and the quality of your effort, not the result.