What clue does the reader have that John is experiencing turmoil in his life in the novel, Money: A Suicide Note?

The novel opens with an author's note explaining that the novel is basically a suicide note from the main character, John Self. This indicates that John is in a position of turmoil in his life; furthermore, he is unable to find satisfaction in his job or his home life. Note, this doesn't mean that John's character will take his own life... it is the reader's clue that John is living on the edge.