心情差的英文短句如下：
1. I'm feeling down today.
2. I'm in a bad mood.
3. I'm feeling a bit down in the dumps.
4. I'm feeling grumpy and unpleasant.
5. I'm not in the best of spirits right now.
6. I'm feeling blue today.
7. I'm feeling low and unhappy.
8. I'm feeling a bit down in the dumps lately.
9. I'm feeling stressed and unhappy lately.
請注意，以上句子只是表達心情不好的一種方式，您還可以根據自己的具體情況和需要選擇更適合的表述方式。