Brake Disc Pads problems of the 2005 Nissan Sentra

My car was supposedly fully inspected on October 2010. It had been checked about three times that same year by Nissan dealerships. On March 8, as I was exiting I-35, my brakes would not respond. I kept pressing the brake; I didn't raise my foot and push, I just kept pushing deeper and deeper. I braced myself for impact, but miraculously, the car stopped just a centimeter away from the car in front of me. The warranty ran out on October 2010, so I took the car to a non-Nissan mechanic, who found that my car was missing brake fluid and that all my brakes were worn out. They all need to be replaced, including brake pads. This did not happen overnight. No Nissan dealership ever told me about any problems with my brakes. Town north Nissan in austin were the ones who last inspected my car, twice in a period of six months. Before, that, I took my car to charlie clark Nissan in harlingen (which has the worst service ever; they tried making me pay for things that were covered under my warranty). I could have crashed; I could've killed others and myself. I don't know who else to resort to, because based on prior experience (I've had issues with my a. C. , windows, and other things before), Nissan does is rude and does not help out. So, I doubt they'll help me now that my warranty has run out. My brakes did not wear out over night. A huge accident could have resulted due to the Nissan's negligence.