Front Air Bag Sensor Control problems of the 1997 Kia Motor Sportage

Engine check light is on, the car is stalling, the air bag lights are on. I am afraid that they will deploy at any given time. Almost killed myself and my daughter on the queenboro bridge, I was going 40 and all of a sudden the car accelerated on it's own, I applied the brakes, but they had turned hard, I had no brakes, put emergency brakes, but nothing, when it was nearing an accident because I had to stop I threw the car in neutral which slowed it down enough for me to safely put it in park in the middle of a bridge. The cars engine roared when I put in park I couldn't move or fear of killing myself. The locks on the car keep opening and closing by themself. It needs 2 quarts of engine oil every month. I am totally dissatisfied with this car.