describe the gatsbt's emotional state when daisy arrives at nick's house

Gatsby's emotional state is like that of a terrified little boy; he is a complete wreck.

"An hour later the front door opened nervously, and Gatsby, in a white flannel suit, silver shirt, and gold-colored tie, hurried in. He was pale, and there were dark signs of sleeplessness beneath his eyes."

When Daisy arrives he panics to such a degree that he claims that he's made a mistake.

“This is a terrible mistake,” he said, shaking his head from side to side, “a terrible, terrible mistake.”