Don't mean to freak you out, but sometimes a chicken can get "stuck in molt". This is what happened to one of my Brahmas. Last fall, all three Brahmas went through molt. One, especially, went at it so hard and heavy, she looked like she got chewed up in a garbage disposal. She went neurotically broody at the same time, sitting on an empty nest day and night for over a month. She recovered and came out of the ordeal looking for all the world like a brand new chicken. She would have taken a blue ribbon at the fair for sure!
Her sister recovered also, and looks almost as glamorous in her new foliage. But their other sister, even now, is an embarrassment to the poultry race. She has mostly the same frowzy feathers she had during her fall molt. At least the persistent naked area on the front of her neck is starting to fill in. But that's due to my coming on this forum and posting about her sad condition and being told about being "stuck in molt" and given advice.
Most of the time, chickens molt, they lose a few feathers, they quickly get replaced, and molt is over before you know it. Sometimes they molt and you aren't even aware of it. But this girl got interrupted, stress can do it, and her molt never reached the stage where the old damaged feathers fall out and get replaced. I'm beginning to wonder if she'll spend the rest of her life looking like something the cat dragged in.
I've been giving her extra protein, actually shamelessly spoiling her, but beyond her neck feathers finally growing back, she continues to look like a homeless hen.
Man! I hate molt! Good luck with yours!