cold feet vs disappointment

cold feet

noun
  • A feeling of nervousness or anxiousness causing one to reconsider a decision about an upcoming event. 

  • Used other than figuratively or idiomatically: see cold, feet. 

disappointment

noun
  • An example or the act of disappointing: a circumstance in which a positive expectation is not achieved. 

  • The feeling or state of being disappointed: a feeling of sadness or frustration when something is not as good as one hoped or expected, or when something bad unexpectedly happens. 

  • Something or someone that disappoints: that which causes disappointment. 

How often have the words cold feet and disappointment occurred in a corpus of books? (source: Google Ngram Viewer )