Racial Slur Grounds For Civil Lawsuit?

An individual repeatedly provoked me trying to draw me into a fight. When I refused and walked away, he yelled out a racial slur. At this remark, I returned and "accommodated" the individual with a backhand. He suddenly changed his demeanor and called police. I was charged with misdemeanor ault. Weeks later he then filed a civil lawsuit claiming I broke his jaw (a simple backhand!?!?) and the charge was then upgraded to a Felony. He is demanding thousands of dollars to settle. The Police Report stated no bruising, swelling or blood was observed during time the individual was being interviewed. He was articulate and clear in his speech, and he refused any medical attention at the scene. Furthermore, he waited almost a week before he sought medical treatment for his "injury". Question: Do I have grounds for a counter-lawsuit and what charges should I file?