I'm losing my mind. 我失去理智了。

　　You've got to be out of your mind! 你肯定疯了!

　　What are you doing? Are you out of your mind? 你在干嘛?你疯了?

　　There's too much homework. I'm losing my mind! 作业太多了。我快要疯了。

　　Calm down. Let's take a look at it. 冷静一下。我帮你看看吧。