Chicken attacked got better now getting worse yellow diarrhea

[Adktriguy]

We had a chicken attacked two weeks ago we toke care of her and she seemed to be getting better. Walking a little and eating then she stopped suddenly and cant walk and wont eat or drink. She has a yellow and black diarehea ... what can we do she wont let us feed her and she really has regressed a few days ago she seemed ready to be outside and on she was even pecking at the ground and eating some seed and bugs. This is our first backyard flock and our first issue with an injury. FYI we dont know if she was attacked by cat or coon but she lost most of her feathers had some pretty good wounds.