My chicken won't stand up - also has dropped wing?

[Janine989]

Hi I have about a 6 month old Plymouth rock, as it is winter she had not laid yet. I noticed she was looking a little off colour then 3 days ago I noticed her wing was hanging and this morning she was just sitting at the back of the coop. I picked her up easily which worried me as she is my most scatty and took her inside with food. Went to work she has drank a lot of water but only done one poo in 12 hours and is not eating. I tried to wrap her wing but now she can't even stand up herself so I took it off thinking she was just being a drama queen but now I am really worried. What could be wrong an how can I help her? She is in my room in a box next to my bed so I can monitor... I really don't want to loose her I have already lost two to colds and I am feeling like I just had them all healthy!

If it was worms or lice it would be affecting all of them? I don't have her on laying mash as someone told me it can be bad to feed to it them before they start laying?

I really don't think she will make it through the night