Fretting about it won't help.

苦恼于事无补。

I was working all hours and constantly fretting about everyone else's problems.

我一刻不停地工作着，还一直担心着其他人的问题。

Mary got your Sunday clothes ready, and everybody's been fretting about you.

玛丽为你准备好了礼服，大家都在为你担心。

What are you fretting about?

你为什么烦躁不安?

You are fretting yourself needlessly.

你在不必要地折磨自己。