I see. I missed the cloudy eye. Which BTW could be from many reasons, even as benign as stress, thicker mucus, light abrasion, or adjustment to new water pH, and hardness. But yes, could be due to infection. Or due to hitting the tank wall as Polypterus said above.
Curved back has never been an infection symptom as far as I know, but I am not all knowing.
In any case, the OP seem to have lost interest in this thread long time ago, so it feels like kicking a dead gar...