Berlin is 11 months old, male, intact. He was socialized extensively and exposed to as much as possible from a young age. He has always been confident, sure of himself, never displayed aggression or fear...but that has all changed these past few weeks. He has begun displaying fear behaviors, today on our walk, someone let off a few small fireworks, and he booked it, and wouldnt stop until we were home. He shuts down from minor corrections (pulling on the lead when tracking/not getting something right - just gives up) He has been showing aggression to a few dogs...and is definitely being reactive toward them. *sigh*. What happened...and what do I do?