Please break that post into paragraphs. Also, add your tanks and fish to your sig so we can figure out what's going on.
What do they have? You said you were treating with ich medicine but you didn't say anything about fungus. For fungus I would say melafix is your best bet.
Never, ever add salt to a tank with cories, but I think you know that now. There's a pinned article on it in the catfish section.
Once the ich is gone, if you have it, lower the temperature and continue partial water changes to lower stress.
You have too many fish and are overstocked. The ammonia should be at 0, as should nitrites. pH should be somewhat acidic, IMO, so try lowering it if you can.