other fish would probably bother him. try melafix... and take the carbon out of the filter on your hospital tank. i have no idea what a fungus tablet could possibly be, but melafix will probably help out the little guy.
if it was fungus, you would see spots on him or the ends of the fins looking fuzzy, but if he just got beat up, it'll look like there are just pieces missing. melafix will help the latter because it's kinda like fish neosporin, it'll stop any infections and help heal the wound.