(one's) own worst enemy
Causing complications to one's life or keeping oneself from success; self-destructive or self-sabotaging. Tommy's becoming his own worst enemy with the way he's been skipping school lately. She always sabotages a relationship when it's going really well because she's her own worst enemy. Mike gets so anxious on dates that he has a hard time making conversation—he ends up being his own worst enemy.
Farlex Dictionary of Idioms. © 2024 Farlex, Inc, all rights reserved.
*one's own worst enemy
Fig. consistently causing oneself to fail; more harmful to oneself than other people are. (*Typically: be ~; become ~.) Ellen: My boss is my enemy. She never says anything good about me. Jane: Ellen, you're your own worst enemy. If you did your job responsibly, your boss would be nicer.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
your own worst enemy
COMMON If you say that someone is their own worst enemy, you mean that their own behaviour causes most of their problems. In a way I'm my own worst enemy — too critical and hard on myself. The patients are their own worst enemy. They keep missing appointments.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012