anguish vs regret

anguish

noun
  • Extreme pain, either of body or mind; excruciating distress. 

verb
  • To cause to suffer pain. 

  • To suffer pain. 

regret

noun
  • Emotional pain on account of something done or experienced in the past, with a wish that it had been different; a looking back with dissatisfaction or with longing. 

  • The amount of avoidable loss that results from choosing the wrong action. 

verb
  • To feel sorry about (a thing that has or has not happened), afterthink: to wish that a thing had not happened, that something else had happened instead. 

  • To feel sorry about (any thing). 

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