chick issues

[ilovemychook24]

Today i went out to check up on all my hens since, my hens all decided to have a broody frenzy, so chicks absolutely everywhere. i skim checked each pen and didnt see any issues or at least nothing overly noticable, i was just about to head back home when i turned and i noticed this pancake of black in the nestbox, at first i expected the worst "its dead" i thought to myself sighing but when i went over and picked it up he brought his head up and gasped and repeatedly did so, first thing i thought was that it had been stuck in the nestbox and had become extremely dehydrated (since it is quite hot today), so i gave it water and it drank willing (its eye closed still), i gave it a drink every 10 minutes or so until he wouldn't bother, he did perk up a little eventually attempting to cheep and opening it eyes to take a look at it surroundings at some points but then everything went downhill, he started twisting his neck up and down, side to side (quite slowly). at that point a few mites and lice crawled out onto my hands so i thought maybe he had a problem with mites and lice so i powdered him, once he was fully powdered i placed him in a clean, powdered nestbox by himself and i was watching over him when all of a sudden he did these kind of flip things, flip here, flip there (not literally flipping but almost like tossing violently) along with its neck twisting every now and then, what is going on?? i have no clue on what this is?? or how to cure it? and i know it'll probably die and it hurts me to say it but i need to know how to cure this for future issues