all ready upped the temp,oxygen and added saltwell for whitespot, up the temperature do regular water changes and add some salt.
melafix and pimafix by API are good for treating fungus and bacterial infections because they are compleatly natural, however carbon will remove them

Not really any general meds, as good medications are often too potent and put too much strain on the fish to be mixed so to make a general med, very weak doses have to be used.
Waterlife Paragon claims to treat quite a few things but it is strong and should not be used lightly. If it is ich (white spot), treat for that and if you don't know yet, just keep his water clean and observe.