Steering Related Problems of the 2003 Mercedes Benz E320

Steering problem

I was driving on route 5, branch Ave. , near clinton, MD, about 30 mph, down slight decline of a hill, approaching a place in the road where cars can enter the highway from both the left and the right. As we normally do, I pressed on the breaks to slow down, in case one of the cars sitting on both the left and right, decided to enter on to branch Ave. My brakes failed - the foot peddle went completely to the floor when I was trying to slow down, there was little to no control in the steering wheel and I looked at the dashboard and it was lit up in red warning lights , first saying brake need maintenance (or something) at first. I manage to get the car to steer towards the right to get on the side of the road, hoping the rough terrain would help to slow the car to a stop. By this time the red warning lighted up dash board said stop, brake failure or something. The car finally stopped and I turned if off. I am 59 year old woman and was absolutely petrified - my whole body was shaking from the fear that I was going to wreck on this busy highway. Luckily for me the cars waiting to enter the road, did not and cars on the highway slowed down and went around me while the car was coasting towards the side of the road. There was no warning light telling me to get the brakes services - they just failed while I was driving on the freeway. I called mercedes roadside service for them to pick up the car. After an hour and they had not arrived, I turned the car on, there was no red light. I pressed the brake and it didn't go to the floor but it was soft and went nearly to the floor. I kept pumping the breaks - something I used to see my father do - thinking that would bring the breaks back up so that I could at least drive back home to await service truck. I let mercedes service know, then I slowly drove back, side roads, pulling over to allow cars to pass until got home.