I'm sorry to hear that, I don't know that there is a lot more you can do. It may just be his time. You can try a vet but most people don't take their fish to vets because there usually isn't anything a vet can do. Maybe you can try a special treat (like the blood worms) to see if that will at least get him to eat something.
I'm really sorry. It's hard to see a pet sick no matter what it is. Sometimes even worst with a fish because there isn't a lot that can be done even by vets.
Jackie and her little babies.
Candi- Italian Greyhound
Cash- Italian Greyhound
Jasmine- Tabby cat