My chicken is sick! What's wrong?

[Fiasco]

I have a small ameraucana/bantam mix hen, about two years old. She hasn't started laying eggs like my other hens have, she wont eat anything (at least today), her crop is full, and she's been laying in her nesting area with her eyes closed, not responding to my voice like usual. She hasn't moved from that spot in the coop all day. She does open her eyes a bit when I pet her, but she still looked sickly. Also, her poop has seemed kind of watery since Christmas, and now it looks clearish too.

A few months ago, I think she was sick with something else and never completely got over it. I'm not sure if it could be related, but just in case! She had been losing feathers, and she acted weak without the energy to flap up to a perch like the others. She had lost a lot of weight, and I could almost touch my fingers together behind her breastbone. She also had diarrhea. I thought at first that it was impacted crop, because it seemed full and hard, but decided it wasn't because the crop wasn't so full the next day. So I gave her some probiotic powder (meant for parasites) in her water, for about two weeks, as per a vet's recommendation. She seemed better after that, with her feathers growing back in and gaining her weight back, but she still had diarrhea like before (the wateriness I mentioned above).

Do you have any idea what could be wrong with her? I would appreciate any advice. She seems so bad today and I'm worried about her! Thanks in advance!

 

[Fiasco]

Update! Good and bad news. She was up and walking around just now, but...she is limping a lot, and upon a closer inspection, one of her feet is all swollen up (pictured below, it's the one she keeps curled up). Also, her crop is huge (bigger than a golf ball, closer to the size of a tennis ball) - and she's a tiny hen! I felt it, and it's really hard. I could hardly feel any give at all, but I do think I felt something hard and stringy, maybe hay or grass. Maybe impacted crop? These sound like two completely separate things, but I don't know! Any ideas??