Sounds like your catfish may have been poisoned by the tablet form meds. You said the cat fish was pushing the med around, it probably started nibbling at it which is their nature. This med is suppoesd to dissolve into the water not be eaten straight by the fish. But you cant tell a catfish or a pleco not to nibble when thats how they eat algae wafers
I had few tetra that looked like patch work of white spots when they had ich, could hardly see their natural colours. But a few days after I medicated with liquid type med the ich spots reduced.
By the second recomended med dose the ich spots were gone. It took about 6days for all the ich to leave on each affected fish depending on when they developed it.
Try to think of it as when a child has chickenbox, the recovery is a process rather than instant fix