It is law that they must prosecute him and there is physical evidence as well as your own child encouraging you to have contacted the police to begin with. They will prosecute now with or without your testimony. For me, it was very healing to go to court and give a statement. I had to for every woman affected by DV that was there feeling like you do and I did. My situation got so bad, the police officers involved got special permission to take paid duty to escort me to court and back and the court assigned a victim witness person to help me with filing a restraining order as well as to be there to just hold my hand at court dates. See if that is a resource for yourself. You are stronger than you know just surviving this situation so give yourself credit that no matter what, you can leave this situation and not continue to be manipulated by an abusive man child.