Separation From Abusive Ex With Joint Custody

I need advice in my current situation.

I separated from a possessive and abusive ex partner over a year ago. Currently have joint custody with our child and I never called the police neither have I taken legal action on them for the abuse. Over the course of the year I have experience verbal abuse and intimidation.

I did my best to keep things civil for the sake of our child. However for my safety I arranged to have the transitions of our child in public places. Attempting minimal contact.

The last time a transition took place my ex ended up assaulting me in front of our child.

My ex apologized to our child and left the scene. I ended up calling the cops for the first time gave them all the information. They gave me the options to file a restraining order and to take legal action for the assault.

Due to the fact that we have joint custody and me not being familiar with the legal system I don't know how this is going to affect things in my current situation.

If I go with the options the officers gave me, what will happen with the joint custody. How will arrangements going forward with the joint custody look like.

My understanding of a restraining order is zero contact.

How quickly will my ex be aware of all of this? I am concerned that my daughter may not be safe during this process.