I am sick and tired of doing homework.
我对做作业感到厌烦.

----------------------------------------------------------------------

Sick and tired of something 可以视之为一个片语, 所以并没有 sick (生病) 的意思在里面! 例如贩卖机老是吃钱, 你也可以说 I am sick and tired of this vending machine. 还有一句话也很有趣, I am so sick and tired of being sick and tired. 就是说你对于老是感到厌烦已经感到十分厌烦了, 我想这是很多都市人共同的心声吧.

I am sick and tired of doing homework.

I am sick and tired of doing home work.
I am so sick and tired of being sick and tired.
I am sick and tired of  this vending mashine.