I couldn't agree more with what Glacier said.

As far as the puppy class goes, if they seperated you fromt he other dogs at the other end of the room, well than obviously that was not a puppy socialization class, Your instructor was probably not a good one. You should of dropped out right then & there & found a more reputable trainer. But you can't change the past.
I would seek the help of a behavorist that specializes in aggression ASAP.

How about the breeder from your pup, have you contacted them? They should be able to point you in the right direction.

good luck