If I was me I'd get the goldfish out of there, do a 50% wc, salt it up, raise the temp, and if no change after two days try Tetra Lifeguard. Stuff is going to be expensive as hell on that size tank though but I've had really good luck with it when nothing else has worked. You need one tablet per gallon if I remember right to figure out how much you need for a full course of treatment. It would be $26 for two bottle sizes plus shipping here -
http://www.petcarerx.com/catalog/productdetails.aspx?pid=19940&&id=1777 Just do a search for it, there are some sites that have the 150 tablet bottle for $12 plus shipping.