As you know now,your shedding is most likely either low humidity or underfed or both.Care full anytime placing it in water as to make sure it is not too deep in case it gets tired.You might just want to keep an area under a hide cave or make one with a humid spot in your cage.You can hold it under luke warm water and rub its body front to back and help some off.Mine does not have anything but a water bowl for humidity and I mist him now and then.I really think you problem has been not feeding enough.I doubt its parasites but see how long he takes to gain some weight back and if you dont see anything in a few weeks then see a vet.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,Being a corn snake with the higher metabolism you will want to feed it every 6 days or s

nce a month or so works with large snakes that eat big meals and sit still all day.Corns are always ready for more food.Make sure your feeding a good sized meal,not to big but big enough.Make sure its temps are good,too cold and digestion is a fail and it can get ill.I say its the feeding,mine never had a bad shed but he eats about 2 mice every 10 days.Post pics as soon as you can please.Im glad its alive though,I remember when you got it.Keep it fed dude,no laggin.