2009 Mercedes-Benz C300 brakes problems

I was driving on the parkway at ~40 MPH and attempted to slow down by stepping on the brake. The car did not slow down but accelerated. And struck the car in front of me. Every time I pressed on the brake, the car accelerated so that the car struck the car in front twice. I tried to turn off the ignition and was unable to. Finally, I pushed hard on the brake enough to slow it down and I was ten able to put the car in neutral. The engine raced but I was then able to turn it off.

On 8/8/2013 my information display indicated my right taillight, blinker and brake lights were out. When I opened the compartment to see what type of bulbs to replace I found the problem to be much bigger than expected. The plastic housing that hold the wiring pin, the wiring pin and the brown ground wire were all burnt up causing the lights to fail. I than opened the left tail light compartment and the same thing is happening, there is already signs of the housing burning.