Well you've laid out a perfect example of why many of us "don't go to dog parks".
Your number one jobs is to protect your dog. This dog shouldn’t be around other dogs,She's stressed and now feels she has to protect herself because you didn’t!
More punishment isn’t the answer. You have to decide if your going to continue to push this dog to be around other dogs or give her and your self a break and condition her to ignore other dogs,,,no more dog parks no more doggie friends!
Give up the dog to dog stuff and I think you can fix the damage on your own. If you insist on having a dog park dog...your going to need a qualified trainer!