1) What type of bird , age and weight.
Buff Orpington/24 weeks/ I would guess 2 1/2#
2) What is the behavior, exactly.
Lethargic/ squatting but not sitting/ head bobs like a little kid falling asleep sitting up/ feathers on back of neck standing up once in a while
3) Is there any bleeding, injury, broken bones or other sign of trauma.
4) What happened, if anything that you know of, that may have caused the situation.
5) What has the bird been eating and drinking, if at all.
Layer crumbles, water.....checked crop....seems to be almost full
6) How does the poop look? Normal? Bloody? Runny? etc.
7) What has been the treatment you have administered so far?
Just physical inspection
8 ) What is your intent as far as treatment? For example, do you want to treat completely yourself, or do you need help in stabilizing the bird til you can get to a vet?
9) If you have a picture of the wound or condition, please post it. It may help.
10) Describe the housing/bedding in use
Straw/wood chip coop above run pen
Sounds like eggbound is a possibility. Personally I would give her a warm bath tonight, sometimes that helps to relax them enough to pass the egg - and then keep her somewhere warm and dark for the night and re-assess in the morning. Keep us posted please.
Edited as I didn't read the OP's post properly. Duh.
I had a chicken who couldn't hold up her head and it was botulism. I had to put a tube down her throat every 2 hours and put babyfood and antibiotic into her crop for 2 days and then she got better. Can she hold up her head or has she lost muscle control of her neck? That is what mine did. But now she is fully recovered. My vet showed me how to intubate her and told me what antibiotic to buy.