成天受嘲讽是很令人泄气的。

It's very discouraging to be sneered at all the time.

《新英汉大辞典》

做一件不适合的工作可能是令人泄气的经历。

Working in a job that is a bad fit can be a demoralizing experience.

youdao

尽管菲比耐心十足——我和莎莉也如此——此行中令人泄气的时刻还是不少。

Patient as Phoebe was—as we all were—there were plenty of discouraging moments along the way.

youdao

We'll about what individuals can do, what a country can do, what the world can do to help change what are really pretty discouraging numbers.

我们会谈到个人能做些什么,国家能做些什么,世界又能做些什么,去帮助改变这些,令人泄气的数据

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

I'm frustrated that I can't concentrate on my homework.

我没法把注意力集中在我的作业上，真令人泄气。

I'm frustrated 实战 - SpeakingMax英语口语达人