Shakespeare has a special line in obsessive, consumptive love; love that feels more like death than life. Even where the love itself is unhealthy, unworthy, or foreshortened by circumstance, his descriptions of that morbid state are magnificent. This is Helena, from All's well that ends well, confessing her love for Bertram. No matter that Bertram is a total jerk who spurns her repeatedly until he is tricked into accepting her. The poetry is beautiful, and in immortalising the feeling, it effaces Bertram's peculiar flaws; it survives his unworthiness.
I am undone: there is no living, none,If Bertram be away. ’Twere all oneThat I should love a bright particular starAnd think to wed it, he is so above me:In his bright radiance and collateral lightMust I be comforted, not in his sphere.The ambition in my love thus plagues itself:The hind that would be mated by the lionMust die for love. ’Twas pretty, though plague,To see him every hour; to sit and drawHis arched brows, his hawking eye, his curls,In our heart’s table; heart too capableOf every line and trick of his sweet favour:But now he’s gone, and my idolatrous fancyMust sanctify his reliques.