ruthless hens

I have 8 chickens that I got in November as chicks. I got my first egg March 31st and I think all but maybe 2 or 3 are laying now. I noticed a month ago that my dainty speckled Sussex, Jolene's back looked fuzzy like her feathers were still growing in. Then a few more girls developed this tattered look. But in the past two weeks the problem has gotten completely out of hand. I was changing the water one day and noticed fresh blood on Barbara-Jean's beak ( buff orpington). It was from the behind of Gretta, my sweet earmuffed Easter egger. Needlessly to say I freaked. Yes- there were tears and extreme panic. I proceeded to take each chicken out give them a thurough check-up. All but one had broken feathers on her back and many had red bottoms where they apparently got pecked. The pristine lady, Diana, not sure the breed but one of the smallest chickens, all black with a short beak. She was in impeccable condition. Unfortunately, the problem has snow-balled. The next day Louise, a gold-laced wyandotte, had a quarter sized bald patch in her back. She wasn't even one of the ones I was really worried about the day before. Also, upon observation, I've noticed all but three partaking in bullying or picking. And, perhaps most disturbing of all, Gretta and Ethel don't even defend themselves or run away! They just hunker down and cry until I break it up. I am currently making their outdoor run bigger but will this fix it? I should also tell you that I give them organic 16% layer crumbles, free access to oyster shell, and fruit/veggie/bread scraps and scratch every day in a moderate amount in an attempt to distract them from this behavior. The stress of seeing/hearing this go on is on the verge of giving me an ulcer but I can only imagine how stressed They are. Can anyone help? I have a few other issues but this is by far the most important of my concerns.

 

Thank you so much for this great advice! I'm going to try a combination of the suggestions and hopefully that will nip this problem in the butt.