in love vs lovesick

in love

adj
  • feeling the emotion of love 

prep
  • (informal) Very fond (of an idea, etc.) 

  • Enamored (of a person, etc.) 

lovesick

adj
  • Behaving oddly, or as though in distress, due to being overcome by feelings of love. 

  • Having an aching desire for one's beloved. 

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