以下是一些用英文表達心情不好的句子：
I'm in a really bad mood today.
I feel out of place.
I've had it.
I'm under so much pressure.
I'm feeling down today, I'm just not in the mood for anything.
My mood is low, I'm finding it hard to get excited about anything right now.
I'm not in a good mood, I'm feeling really irritable and easily frustrated.
I'm feeling blue lately, I just can't shake this feeling of sadness.
I'm feeling depressed and it's affecting my ability to focus on anything else.
I'm feeling sad today, I just need some time to myself to process my emotions.
I'm so stressed.
Why the long face?
I'm not in the mood.
I'm sick of...
I'm in a bad mood.
I'm not on my game today.
That's the spirit!