cry your heart out
cry (one's) heart out
To cry for an extended period of time. Poor Jane really cried her heart out during the funeral service. I can't watch those sappy movies because I just cry my heart out every time.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
cry your heart outor
sob your heart outINFORMAL
COMMON If you cry your heart out or sob your heart out, you cry a lot. Note: The heart is traditionally regarded as the centre of the emotions. I threw myself on to the bed and cried my heart out. I had never known her cry, and here she was sobbing her heart out. Compare with your heart out.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012