I found this on another site "As for the white spots, are they tiny, like a pin-point spot, all over the fish, or are they larger, like 1/16-1/8" in diameter? Tiny pin-point spots on a fish is probably ichthyophthirius (Ick). This is easily treated with a 0.3% salt solution in 3 days in warm water, 78 degrees or so. If the spots are few and larger, it could possibly be a fungal growth or it may be epistylis. A 0.3% solution of salt will also kill epistylis. There are several fungal medicines on the market for fish and these fungal spots usually look puffy, like small cotton balls."
But if this doesn't work?? Id say, when your not paying attention go buy yourself a new gold fish.. and replace the dieing one while your not paying attention..(.: I do hope you fishy gets better..really..