Definitely sounds like swim bladder. Really common and not much you can do for it. I tried peas with my goldfish but it didn't seem to help.

Sorry Lenny!

ETA: here's some info on how you can try and resolve swim bladder:

Steps

1 Buy a package of frozen peas, or search in your freezer for the bag you bought two years ago. They are rock hard by now, so defrost them.
2 Take one or two peas and make sure they are nice and defrosted. Take the skin off.
3 Put the pea(s) in the goldfish's tank.
4 Keep trying. If the fish doesn't eat the pea immediately, remove it and try again later. The fish will eat the pea eventually, as all goldfish are perpetually hungry, and require a certain amount of greens in their diet for optimum nutrition. Until the fish eats the pea, withhold all other foods.
5 Alternatively, try feeding live, frozen, or freeze-dried daphnia to the goldfish.
6 The fish should be swimming upright in no time.