Why does Holden not want to have sex with Sunny?

In chapter 13, Holden checks in at the Edmont Hotel and meets an elevator operator who offers to send him a prostitute for five dollars. Holden agrees and begins to contemplate sex, women, and his missed opportunities to lose his virginity in the hotel room as he waits for the prostitute. When the prostitute arrives, she is a young girl with a high voice who makes Holden feel extremely nervous. When Sunny immediately takes off her dress, Holden mentions that he feels "peculiar" and says,

Sexy was about the last thing I was feeling. I felt much more depressed than sexy (Salinger 51).

Instead of having sex with Sunny, Holden lights up a cigarette and has a conversation with her. Holden eventually tells Sunny that he does not feel in the mood to have sex because he has recently had an operation on his "clavichord." Holden then confesses to the reader that Sunny is "depressing," and he feels more sad than sexy. What Holden really needs is to have a conversation with a person who genuinely cares about him. Holden is extremely lonely and nervous, and he is stressed out at this point and has other things on his mind. Aside from being worried about losing his virginity to a prostitute, Holden chooses to not have sex with Sunny, because he is too depressed and upset with life. He does not feel "sexy" and admits that he only feels sad being around her.