Whats wrong with my fish ??

[janalta]

Correct....you don't want to run carbon while dosing with medications...but I would definitely start once you've finished the treatment.

What size is your tank?
Looks like a 55 from the pics.....might want to either add another powerhead, or change the existing circulation around to get better flow going.
Wait until you fix up with water changes, meds, etc and adjust flow once you see what happens