because of crowding and confinement, your chickens are turning into cannibals. Make getting that run the first immediate priority. take off work if you have to. You can temporarily use netting, chicken wire, or nothing. Get it done.
I would risk free ranging right now, because they are dying anyway.
Also, provide as much distraction as possible in their teeny tiny coop. Put different levels in there, and provide hiding places (crates put on their side), haybales, boxes, etc.
Sprinkle boss (black sunflower seeds) in the bedding to give them something to go after besides each other.
Tie a cabbage up and hang it from a rope.
Cut open a squash and put it out for them to chew on
These are things to give them something to do besides eat each other.
Get some "blue kote" it comes in a little spray can. Don't use the other brand of blue antiseptic spray because your birds will scream when it comes into contact with wounds. Use blue kote. Reason is it has gentian violet, and it will turn red blood wounds into purple - chickens are attracted to red/blood and will peck more.