Chippie, I'll leave the advice to the vets, I don't feel I have the knowledge to offer any.
However, I want to address him constantly reverting back negatively to you calling the police. It makes me think that he is trying to make you think that calling the police to protect yourself is the wrong thing to do. Positive reinforcement is the way to show kids, or train dogs, to do the right thing. I think he is doing the opposite and trying to train you not to get the police involved, because they interfere with his being able to control the situation.
Don't allow him to sway what you know is the right thing to do.
M - 9 1/2 years 5/5/16 - Bomb drop - 3 week EA 10/31/16 - We sold house 01/10/18 - D Finalized