As said you should do a water change, but after that put some medical salt into the aquarium, don't use table salt or reef salt only use fish medical salt. Add 1 flat tablespoon per 15 gallons of water, that should fix it.
Use this forum! There's a market place on this and you can rehome it that way, and if you do it on this forum that there's a greater chance of the fish getting rehomed to the right people!