Under socialized GSD puppy

Question
We recently rescued a gsd puppy almost 2 months ago and she is about 4-4 1/2 months old. She gets along great with our other dog (11 month old female pit/lab mix) and even my parents dog whenever I bring him over. After she had her rabies shot we tried taking her to the dog beach but she had an 'anxiety attack' everytime other dogs/people approached her & she cried the entire time we were there, we assumed this reaction was normal and would fade away once she got used to all the other dogs & realized they weren't going to hurt her, but the behavior not only persisted it got worse. We've tried taking her to the dog park but this last time my boyfriend had to leave me there with our other dog so he could take her home. At first she was just scared but once I picked her up she started acting agressive/defensive? (barking,nipping, lunging) towards the dogs that were on the ground trying to smell her. So how can/should I go about socializing her so that these negative experiences are replaced with ones that allow her to feel comfortable & enjoy the company of other dogs in unfamiliar places like the dog park?

Answer
Many people don't understand the importance of early socialization and the difficulty of undoing problems from it.  It is also possible she is going through a fear stage.  Even the best bred and socialized puppies go through them.  I would not take her back to the dog beach when it is crowded for a while.  She may be able to handle one additional dog  when she is with familiar ones.  Just don't push her.

Better leadership on your part may help.  The key to most behavior problems is approaching things using the dog's natural instincts.  Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog.  Life is much easier if the 2 legged pack members outrank the 4 legged ones.  You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/  For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm