Sob your heart out - Idioms by The Free Dictionary
sob your heart out
sob (one's) heart out
To cry for an extended period of time. Poor Jane really sobbed her heart out during the funeral service. I can't watch those sappy movies because I just sob my heart out every time.
sob your ˈheart out cry noisily for a long time because you are very sad: After the argument she spent an hour sobbing her heart out in the bedroom. OPPOSITE: laugh your head off