When you are in a state of mind where you are constantly pessimistic, complaining, or you constantly tell yourself, "I CANT DO THIS or THAT", your frame of mind is in a very negative state.

当你处于让自己一直悲观、抱怨，不停地对自己说“我无能为力”的心境时，那么你的心理状态就正处于一个负面的状态。

youdao

I regret to tell you that I cant go to your birthday party.

我很遗憾告诉你我不能去参加你的生日晚会了。

youdao