My puppy is growing up too fast!

Annie is growing up way too fast for me! These photos are only about a month apart in the same spot in our kitchen.
We went to the dog park today with hopes of meeting up with Annie's puppy pack.  It was nightmare of a walk.  When we first got there, a pack of about 8 little dogs (all off leash) were walking toward us.  I kept Annie on her leash and thought the ladies and dogs would just walk by.  The whole pack stopped because Annie being a puppy was too cute not to want to pet.  I explained that Annie has been attacked three times by little dogs, so I don't let her get to close anymore.  I know sooner said that when one of the rat dogs went after Annie.  I was prepared this time (had my hiking boots on) and got my boot between them and was about to punt kick the rat across the park when the owner grab it.
We then went down to the dog park and no on was there.  This was the first time we had the park to ourselves so we played fetch.  Annie was having a great time and was actully bringing the balls back to me.  Three big mastiffs, full of energy then came into the park. Has soon as they were let off their leashes, they went after Annie.  She started screaming and ran to me. Now I'm in the middle of these huge dogs barking and nippy at Annie.  I smacked the biggest male dog on the head and knee it in the side as I was saying "NO" in my very alpha dog voice. Lucky for us another big dog came into the park and the mastiff pack went after it.  This was our cue to leave. As we were leaving the park the mastiff owner was kicking his dogs (because they were at this point not listening to his commands) to get them to leave the other dog they had cornered into the fence alone. The lady of the other dog was asking if they were friendly and from her body language she was very scared.  Really, do you think it's a good thing for anyone to be surrounded by out of control mastiffs?
One of the things the "dog whisper" talks about is don't go into a dog park until you are sure of the dogs inside. If this lady had paid attention to what was happening to Annie, she would have been warned not to come in.