You need to tell us what the consistency is of that cream colored blob. If you slice through it with a knife, is it like cheese?
If so, your hen has a reproductive infection called salpingitis, and if she is now lethargic, she's most likely in the final stages of this disease, beyond the reach of an antibiotic.
Just last month I had a nine-year old hen die of this. Her first symptom was a year ago when she stopped laying. But she was getting pretty old, so I missed seeing that it could also be from infection since she was behaving normally up until a few days before she died.
You can try giving her an antibiotic, but it is most likely too late. Once the pus from the infection, and that's what the cheesy stuff is, shows up in the poop, the infection has progressed so far that treatment is usually not effective.