the bane of somebody's life/existence

bane of (one's) existence

The source or cause of one's misfortune, unhappiness, frustration, or anxiety, usually used hyperbolically. I swear, this project is the bane of my existence. I've been working on it for months and still haven't made any real progress! Jane has been constantly annoying me all week. She's been the bane of my very existence!
See also: bane, existence, of

the bane of somebody’s ˈlife/eˈxistence

a person or thing that makes somebody’s life unpleasant or unhappy: That car is always breaking down! It’s the bane of my life. OPPOSITE: a ray of sunshine
See also: bane, existence, life, of