How and why does Kay reach out to Simon as noted in the nonfiction book, This Is Going to Hurt?

Kay connects with Simon on Facebook one early morning, as a result of Simon's suicidal post. Kay reaches out to Simon in an attempt to comfort him, letting him know that he is a doctor and that he can talk to him. Through the book, the reader sees Kay and Simon maintain a long relationship with Kay acting as a sort of therapist for Simon.