KNGSTN, Lisa has provided some excellent advice, so please take heed to it. Dog parks are just an invitation for trouble! I don't really have any advice on curbing DA since I don't really have any experience in this area with the breed, but Lisa and many others will provide excellent advice for you and I do hope you take it in and follow it. Best of luck to you and please keep us posted.
You didn't lose your girl, you just lost your turn!
"In this breed, there's no such thing as an expert! The day someone says they're an expert, they need to walk away from the dogs, because someone's going to get hurt. You should be learning something new every day." John Maynard-Circle M Kennels