My ex hit me, we got into a fight, and now is pressing charges against me. What am i looking at?

We were at a church parking lot in the car when this all happened, she Stared the fight by hitting me several times to my face, then proceeded to begin her attempt to stab me with her keys. I then began to fight back(slap to her face and told her to stop hitting me). She continue to stab me in the neck leaving several marks. She then started kicking me in my jaw. I was forced to have to restrain her by wrapping my arm loosely around her neck giving her a pocket to breath but in a position where she could no longer hit me. She continued to struggle until she was free striking me to my face again. This is when i realized she was not going to stop attacking me. I then had no other choice in my opinion but to fight back until the situation could be neutralized. Once she was done attacking i stopped fighting back. No other strikes where thrown. I get out the car she locks the door and pulls out the parking lot. Nearly hitting me with her car i had to jump onto hood to prevent being ran over. She began to "floor it" shaking the car vigorously until i fell off then sped away. Now she is pressing charges against me for assault. The only witnesses to this case are me and her. Her sister was in the care for about 5 minutes hours before the situation and only heard the argument. Later the same day her father came to my house and threaten my father "if he sees me in the streets hes gonna get me." We live in the same neighborhood. What am i looking at.