Seems like you need to win your case. Whether that is a result of getting a dismissal or winning a jury trial. The good news is that you haven't plead to the charges yet. Often people plea either guilty or no contest not realizing that the charges will be on their records forever. The specific facts of a case are always very important but it does seem like you have a defense. Also, assaults of this (or any nature) have some of the highest rates of acquittal of any type of criminal charge.
You must hire a lawyer. Even if your wife does not want the charges pursued, chances are that the state will pursue them anyway. You will probably have to go to trial.