I think that it may be best for you to consult with a criminal attorney in your area to help with the matter.  Prosecutors do not like just dropping charges against a party.  They have to have good reason to do so and they need some help sometimes just putting things "in perspective."  I am unsure that you can just file a "counterclaim" in the criminal world of prosecution. That is a civil term of art.  You would have to fill out a complaint as a complaining witness.  What happened between you may not even be seen as a defense or it may be depending on the facts as they unraveled.  Get help.  Good luck.