Sorry Rachel - only me...but in a way I think you are right - there is no way you can pussyfoot around this.

The main thing to establish is the reason for the aggression - is it a fear based response or is the dog truly hating other dogs for a dominance or territory point of view.
This can be a hard thing to work out on your own, especially if behaviours have only surfaced after the dog has been with you for a liitle while. I seriously suggest a couple of sessions with a behaviourist. If you get the cause wrong then the treatment is going to be wrong and may aggrevate the situation to the point where a cure is out of the question. If you choose to seek professional help make it clear that the question you want answered is what the root cause is - not twenty sessions to cure it! If you are hapy with that person and they make sense to you then go with it.

I really hope it all works out for you as you have tried so hard with this dog. Let us know how he is doing, please.