I had a pullet, about 7-8 months old last fall, who went into a mini-molt and had symptoms like yours -- except her comb became a little less red. I posted and Speckledhen told me they can have a mini molt; I would have never guessed it. My girl dropped feathers here and there, but not like a hard molt. She stopped laying eggs. She nearly stopped eating and she became quite a bit thinner. I started checking her crop at night, on the roost, and found it was empty. That wasn't her usual robust appetite. So, I brought her inside, nearly every evening, and hand-fed her something nutritious with some extra vitamins, protein and fat. Usually it was a scrambled egg or scraps of fish (lucky girl got salmon a few times!). This went on for a couple months. She eventually came through it, and her appetite came back, her feathers were luxurious and her eggs vastly improved.
Maybe yours is in a type of mini-molt too?