Hi Jessica
I'm sorry your hen is sick.
Can you post some photos of her poop?
How does her abdomen feel - any swelling, bloat, feeling like fluid filled?
When was the last time she laid an egg - was it normal?
Is her crop emptying overnight?
I encourage you to seek vet care or at least take a fecal sample for testing of worms, cocci and bacterial infection.
If all she has been eating for weeks is worms, cheese and eggs then she is most likely deficient in the nutrition department. Offer some all flock/flock raiser type feed - these can usually be found at your local feed store (something like Purina Flock Raiser 20% protein). Add some poultry vitamins to her water - Poultry Nutri-Drench is good (put in the water or direct dose her at 1ml per 3lbs). Worms, eggs and a very small amount of cheese are fine as treats or add in to her normal feed. Some chickens like their feed wet, so you can wet the crumbles, add a small amount of yogurt and egg to her feed to see if she will eat. Give her a small amount of fresh chopped greens (Kale, Mustard greens) or chopped fruit (apple/grapes) as a treat. Be sure to make poultry grit available (crushed granite) this will help her grind/digest food. Also since she is of laying age offer some oyster shell free choice.
I understand you were initially concerned that she may have Cocci. Fecal testing can rule that out.
I see that you have her under a heat lamp. If she is inside, she may not need the extra heat. A sick chicken does fairly well at 75-80F. She's fully feathered, so check your temperature to make sure she is not too hot.
Keeping her hydrated is important. That's good that she is drinking. I know you are doing everything you can to help her, you're doing good, so don't get frustrated
Let us know how she's doing.
