I don't know what hits me. I fly off the handle for no reason.

我也不知道怎么了我经常莫名其妙地发脾气。

You should control your temper. You can't yell at people who care about you.

你应该控制自己的脾气你不该向关心你的人发火。

重点讲解:

I always lose my temper for no reason.

I fly off the handle for no reason.

表达“我经常莫名其妙地发脾气”可以说：I always lose my temper for no reason.短语lose one's temper指“发脾气”，但口语中也可以用俚语fly off the handle形容“突然失去控制而勃然大怒”，这样表达更地道。