SICK ID SHARK HELP PLEASE

[Chummybumby]

My 6 inch ID is just laying there, it's still alive the gills are moving, but it's just laying there. I have noticed that its body had a tiny little hole under the stomache area before, but after i have used Melafix, the hole is now coverd with pink muscle tissue ( i assume that is ), and also the there's like, a tiny sheet of skin peeled off from the tail fin area.. Please help my sick ID shark , he's my favourtie fish in my 100gallon tank .. Please guys ... Thankyou

 

[Chummybumby]

by the way, i have checked the ph and ammo level, they are both fine.. even the temper is about 27 C . I don't know what's wrong with my ID shark,, is it possible to cure him back = /