What are my options, can I counter sue and hopefully win?

Two years ago I was involve in an accident. By law it was constituted my fault as I was making a left hand turn and changing my direction. However, the driver if the other car was in the "right lane exist" lane and kept going straight and so when I started to ten on a yellow light she kept going and slammed against the front of my minivan. She was jumping and yelling and cussing me out and I had my 15 year old brother with me in the car. Now two years later, tomorrow being the limit to being able to sue, I received a package from her attorney saying she is suing me for $1,000,000. She claims I was under the influence of hard drugs and drunk an that she sustained severe internal and external injuries which have prevented her to work and move her shoulders. It says that these documents and doctors reports cannot be provided at the moment as they do not have then. What is my best option. How can I win and prove that I was not under the influence?