MY FISH IS SWIMMING UPSIDE DOWN??!!?

fancy goldfish such as the black moor have a long history of losing control of their swim bladder. the swim bladder is what allows them to be bouyant. without control of this the fish will either sink to the bottom float to the top, or do what yours is doing. This is not something that is fixable. he will be this way forever. sometimes it is caused byoverfeeding him for a long peroid of time causing him to become "bloated". as long as he can go to the surface and feed that he can live that way. but chances are he wont survive much longer. although it is possible for them to live several years that way.