When his lover dies who was the hero that could not bear to be without her?

The hero who could not bear to be without his lover is Orpheus from Greek mythology. Heartbroken by the death of his wife, Eurydice, he descends into the Underworld to retrieve her. His enchanting music touches the hearts of Hades and Persephone, who allow her to return on the condition that he not look back at her until they reach the surface. Ultimately, his inability to follow this rule leads to her permanent loss, highlighting the depth of his love and despair.