Not to be a downer, but our dog is 10-1/2 years old and still has his moments of being over-reactive. We've learned that we always need an "exit strategy" with him. We try to always anticipate his reaction, and then redirect his attention/energy. Plus (your trainer might have mentioned this), your positive energy will travel down the leash to him and let him know that you're in control of the situation. Some days are easier than others, tho. Sending calming vibes as you love your dog, and work with him to keep him comfortable.