Chicken probably had a sour crop, but he only likes to drink water, and doesn'w want to eat feed.

My 5-6 months old cockerel probably had a sour starting 4 day ago, and lasting for 48-60 hours. His breath smell a little bit sour 2 days after I saw the symptoms. I think his crop is empty yesterday, so I gave him only water, to see, if it will go to it's stomach at a normal rate. His crop is almost empty, 8 hours after he drunk a lot of water, so I think, that it is ok to feed him feed today. However, when I tried to give him feeds on his feeder after giving him water, he doesn't want to eat any of the feeds. I use dewormer, and probably overdosed him with fenbendazole(way more than 20mg/kg for 3 consecutive days or for 1 day, since I saw him vomit a lot of water, after drinking too much) last week. Also, I accidentally stepped on his head(without putting my full weight on my leg since I noticed it while doing it) about 2 weeks ago. I only see minor bruises on the head(none on the neck and other parts of his body), and he can't move his right eyelid for several days. I applied betadine and triple antibiotic ointment on the bruises on his head, and he can move he can move his right eyelid normally since few days ago. I don't think that he have coccidiosis, since he was exposed to it starting at 3 weeks of age, and 2-5(or 6) months of age.

The symptoms right now: slightly lethargic, droopy wings, doesn't want to eat feed(crumbles), wants to drink a lot of water, diarrhea( it started since more than 7 days ago, I am not sure if it started after he eats the fenbendazole.)

I think the last time I saw feed on his poop is yesterday.