HELP! Sick hen, absolutely no idea what's wrong!

[Small_Feather_Dragons]

I have a hen, about three years old, who came down with something.
Symptoms:

• lethargic
• loss of appetite; not drinking either
• won't respond to other flock members
• poop is almost entirely liquid, a little yellowish
• crop seems to be filled with fluid

I picked her up and palpated her abdomen (to check if she was egg bound) and she vomited on me. It was very liquid with a little bit of solid, and seemed basically like feces because of the smell and the look of the flecks. I put her down, and when I got her again later is when I noticed that her crop is full of fluid.
My mom tried to feel in the hen's vent and see if she was egg bound too, and more liquid feces came out.

I'm have no idea what's going on, so any help is appreciated. I had another hen die recently but it was a completely different situation (she deteriorated over a period of over a week but I couldn't cure her no matter what I did)

 

[Kiki]

What do you feed her and do you offer grit?
You may want to real through this:
Impacted, Slow and Sour Crops - Prevention and Treatments

 

[Small_Feather_Dragons]

What do you feed her and do you offer grit?
You may want to real through this:
Impacted, Slow and Sour Crops - Prevention and Treatments

We just feed them layer pellets, and sometimes scraps from the kitchen like tomato bits, boccoli stems, etc. We don't offer grit, and in fact it's not something I've heard of using before.

And I've been doing some research, and I do think it might be sour crop at this point

 

[Small_Feather_Dragons]

Update: I helped her to vomit yesterday, and she seemed a lot better than before. Gave her a little bit of moistened layer ration, and some organic, natural yogurt, but she didn't touch it. She did drink all the apple cider vinegar water I put out for her.
She's doing better today, but I suspect that she might be having difficulty in laying an egg now.
Also I think she's just weak from lack of food, so should I try to syringe feed her some mashed up pellets and yogurt?

 

[Kiki]

I'm glad she is feeling somewhat better!
You could oak her in a warm epsom salt bath to see if that will help her pass the egg, but if she is not eating you may wan to consider tube feeding her.