This is a very emotional time for you. I had cold sweats just reading that she had started the D proceedings.
It's not surprising then that you let your emotions get the best of you. When she told you all that you did wrong, the better reaction would have been just to validate. But you probably know that by now. Also, when you run into some difficulties during delicate conversations, such as custody, stop right there. It can be good to solve a few things on the spot, when there is agreement, but when you hit a wall, then you'll need cooler heads and maybe a mediator. Opinions and thoughts can evolve in between conversations, not just during them, so stating your position and hearing hers is already progress.
Calling the cops was likely over the top, but in a way you made a strong stance regarding your desire to be an involved father. We'll see how it plays out, now that it's been done.
Good on you to reach out for support regarding the process. Good luck.
M39 D6 D3 (at S) S 2014-09 D 2016-09
"You can't start a fire sitting around, crying over a broken heart" - Bruce Springsteen.