Greet,
I am sorry to say this but I am not the least surprised. There is an xjerk, controlling and wily who did the same kind of things to me. I have been jailed twice and have 2 batteries on my record when it was all self defense.
The HUGE difference in your case is that you have witnesses.
I, myself would not spend a dime of my own. I would take the state's defense and make sure you have all the witnesses make statements. Ask for a trial. The court does not want a trial. So the attornies and the judge will get together and with the statements decide not to pursue it. Likely they will warn that the two of them part ways and have no contact.
I believe that the two of you will be able to get it over with and go forward.
He is punishing her, in my opinion, for leaving him and being out of his control.