What's his set-up like? Aquarium size, temperature, filtration, etc. I'm sure people on here can help but we definitely need more information 
. It does sound like he's suffering from ammonia poisoning so at the very least do a full water change and add a conditioner that binds ammonia (like Seachem's Prime) to give him some relief.
. It does sound like he's suffering from ammonia poisoning so at the very least do a full water change and add a conditioner that binds ammonia (like Seachem's Prime) to give him some relief.
