Car Accelerates On Its Own problems of the 2019 BMW X5

While I was driving the car alone around 7:30pm 5/13/2021 on the way to a restaurant, after I pushed the gas pedal to pass another car (accelerated to about 50mile-55mile/hr), the car all of a sudden accelerated on itself. I noticed right away after my right foot moved away from the gas pedal (from 50 to 55 then up to 65mile/hr, I stopped my observation since it was getting too fast). I have to constantly hit the brake pedal to reduce the speed for about a mile or two. After I reached the next traffic light, I had to push the brake pedal very hard to make the car fully stop, so I decided to switch the transmission from d to p to see if it could get out of acceleration problem. Once I switched to park, I tried to switch it back to drive mode, however the car did not respond and stayed in parking mode. I then tried to turn off the engine and turned it back two to three times, it just didn't allow me to change back to drive mode. I also noticed that the car made a lot of noise since it accelerated on its own. I realized it was too dangerous to sit in the car in front of the traffic light even with the emergency light on. So I decided to turn it off and left the car. I smelled a very strong burning smell even though I quickly moved away from the car. I waited on the street side for about 2-3 minutes and went back to the car, I was finally able to switch to d mode and drove away slowly. I had similar problem happened last year around October for 3-4 times (not as bad as it was today, I can turn engine off and turn it back on, it will return to normal) and I brought the car back to BMW dealership (BMW at gwinnett place in duluth GA, where I bought the car in Nov 2019) and they won't be able to create the problem. The technician just told me to drive slowly (25-35mile/hr for the first 3-4 min) everyday at the beginning. I recorded two videos at the traffic light.