How does Fitzgerald achieve a melancholic mood at the beginning of Chapter 8?

Fitzgerald begins the chapter with a ruffled and exhausted Nick checking up on Gatsby in order to see if he can get him to leave until news of the accident blows over. The melancholy arrives when he talks about spending the night in front of Daisy's home.... the worry...... the sadness, and a sense of hopelessness we haven't seen before.