Sharing wisdom from the trainer we hired. My second golden bit is like that. She had her shots too and walked and played a lot. Trainer told us that our puppy had several different things going on. 1. She had a feisty side and did not yet understand that she was a dog and we were not dogs, too. She needed help understanding pack mentality and learning manners. 2. Our reactions of saying NO loudly or crying out in pain or making a noise like a dog when she ran at us and bit us…were actually rewarding and reinforcing her bad behavior. It made her repeat it because of the pay-off of more excitement. 3. He told us to stay very calm, give NO eye contact and gently walk her or carry her to a safe, quiet “time-out” area. NOT her crate. We made the guest bathroom puppy-proof and safe by having no trash and making sure no chemicals or products to eat, nothing bad out and having a chew toy. She would cry and protest momentarily and we had to ignore her. After 3-5 minutes, we would let her out and we had to be very calm. Trainer told us to stay standing up for a few minutes as a visual cue we were Leader and it was not aggressive play time. If she repeated aggressive behavior, back to time/out. She figured it out pretty quickly that it was not fun to be shunned. The “time-out” was like a re-set for her. and it taught her what the limits were. Sometimes after she would look so pouty like a toddler and look at us and lie down on floor and fall asleep. Pretty soon “time-out” not needed! Puppies will bite and be land sharks but your description sounds so much like what we experienced it. I hope this was helpful. That golden was a wonderful dog—gentle and sweetly playful once she learned. Yours will be too. :)