Unfortunately, many fish from pet stores already come pre-loaded with a myriad of diseases. It sounds like yours might be diseased, and the "floating around" does not sound too good. I agree that you should test your water and make necessary adjustments. If the fish lives long enough, you could try giving it some sort of live food. There are many fish breeders who sell live cultures of worms and many other live foods for next to nothing on Aquabid.com. You just want to make sure that you order something large enough for the goldfish to see and eat. I've had fish that have lost interest in food completely, but when they see something wriggling around in front of them, they can't resist. If you are on a time crunch (which it sounds like you are), you might want to try going to a local bait store and finding something big enough for the fish to see, but small enough so it does not choke (no nightcrawlers!). I would also isolate these two new fish (if possible) from your old ones ASAP. If one fish in the tank gets sick with something parasitic, bacterial, or fungal, it can wipe out your entire tank. Good luck.