The line that the song from ct ii, scene iii, of twelfth night illustrates that the song is about unrequited love is "As I remember the song about unrequited love begins in scene IV. It begins with words: "Come away, come away, death . . ."
Feste sings another exceptionally dismal love tune and, a short time later, Orsino orders Cesario to go to Olivia once more, arguing Orsino's adoration to her.