Sick/Attacked Chicken

[beverlychicks]

We have four chickens, and one has been acting very unusually. It was staying for days at a time in the brooder, only rarely coming out for water. To keep the chicken out of the pen we put her in our garden right on the other side of a gate. Stupidly we didn't really give her much protection and we think she may have been attacked by a possum. She's missing a lot of feathers on her neck, is having trouble moving around, doesn't have much of an appetite and one of her eyes is swollen. Instead of her usual loud squawk, it sounds more harsh and raspy. We did a better job of isolating her, and I've been giving her electrolyte water and apple sauce with seeds. Please reply if you have any suggestions, we really need help! Thank you