I'm sorry, but I have no real advice to offer since I am a new Golden mommy as well. I just wanted to tell you not to feel like it was in any way your fault. I have taken Jax to the dog park quite a few times and I am constantly feeling like I need to step in somewhere. I just try to watch body signals from the other dogs and take Jax out of there when it looks too heated. I guess I'm just a nervous nelly ad well.