Cardinal Strugglling

[marknash]

our benggai cardingal has not been eating for close to a week now, kind of hanging out at the bottom of the tank.. then we noticed his two fins are all shredded up and he had a small hemmorhage spot beside his gill. we thought maybe he got into a fight with something else in our tank... now that spot beside his gill kind of looks like its getting necrotic .. kind of rotting. hes breathing hard. I think hes maybe got an infection of some type.. but im not sure what it is.. or what to do about it... And heres the kicker.. we have no qt tank.
any thoughts?