I've been looking after four young children all day and I really am at the end of my tether!

我整天都在照料四个小孩，确实已筋疲力尽了！

youdao

Thank goodness you're home. You can put the children to bed; I've has them all day and I'm nearly at the end of my tether.

谢天谢地，你总算回家来了。你可以让孩子们上床睡觉了，我照看他们整整一天了，几乎没有耐心了。

youdao

I was fairly at the end of my tether at last, and could hardly find the stamps to answer the advertisements or the envelopes to stick them to.

我终于到了山穷水尽的地步，几乎连应征广告的回信信封和邮票都找不到。

youdao