living death vs nightmare

living death

noun
  • A condition of suffering, solitude, or impairment so extreme as to deprive one's existence of all happiness and meaning. 

nightmare

noun
  • Any bad, miserable, difficult or terrifying situation or experience that arouses anxiety, terror, agony or great displeasure. 

  • A very bad or frightening dream. 

  • A feeling of extreme anxiety or suffocation experienced during sleep; Sleep paralysis. 

verb
  • To have a nightmare. 

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