go to pieces vs rub salt in the wound

go to pieces

verb
  • To become very upset or emotional, to have a breakdown. 

  • To deteriorate, get much worse, fall apart. 

rub salt in the wound

verb
  • To make an injury, physical or emotional, feel worse. 

How often have the words go to pieces and rub salt in the wound occurred in a corpus of books? (source: Google Ngram Viewer )