"Even then he stood there, hidden wholly i

问题：

"Even then he stood there, hidden wholly in that kindness which is night, while the uprising fumes filled the room. When the odor reached his nostrils, he quit his attitude and fumbled for the bed. ’What’s the use’ he said, weakly, as he stretched himself to rest. " The above is quoted from Theodore Dreiser’s Sister Carrie. Briefly tell the situation that leads to Hurstwood’s suicide and interpret his final words—"What’s the use".