And I felt nauseated all the time.

我一直觉得恶心。

If you feel nauseated you feel dizzy in your head and sick to your stomach.

如果你觉得nauseam，意思就是你会感觉脑袋发晕，胃犯恶心。

He wonders if he'll feel nauseated if he'll feel pain when his body's organs give up and stop functioning.

他不知道自己会不会难受，当身体器官开始衰竭并停止工作的时候。