Try feeding him dry bread; stuff that will absorb water in his belly. Also, I'd get fresh, medicine-free egg yolks and feed them to Peewee to try to get more solid stuff in his belly. I'm not sure what to do for the rest though.
If you can get rid of the bugs and give him good food and water he might make it. My homemade recipe for a weak chicken is to take eggs, hard boil them, mash the yolks up, add a little bit of water to it to make it pasty, and feed it to him thrrough a needless syringe. Hope it helps!
It may be a nutrient deficiency. How much sun is he getting? Also, if your roosters are fighting I think it would be best to keep the protective but gentle rooster and get rid of the other one by donating, cooking, selling, etc. My rooster got a puntare wound in his eye and it healed fine but...