Silver Laced Wyandotte - sick

[Duemig10]

My 3 1/2 month old Silver Laced Wyandotte does not look good. Her eyes are closed with what looks like puss on them, she stays by herself, she is not eating or drinking. She just sits there with her eyes closed and she is not growing like my others. It looks like she is just a tab bigger than when I got her. What is wrong with her. I have been putting Terramycin on her eyes and they do not look better.

 

[Eggs4Sale]

You probably already have, but all I can do is recommend is reading the various illnesses in the link:
https://www.backyardchickens.com/forum/viewtopic.php?id=112920

and does your chicken look like this: https://www.backyardchickens.com/forum/viewtopic.php?id=238294

Sorry I can't be of help. I haven't dealt with this before.