Car acts like it wants to shut off

I have been having ignition problems where the key wasn’t connecting properly to start the car. I would turn the key to the on position but it wouldn’t make any noise and the car wouldn’t start. I took it to Firestone and in November 2018 the mechanic installed an ignition switch. They also did a charging check and said my battery was in good condition. The car started just fine after that. A day or two later the same problem occurred again. The key wasn’t connecting properly to start the car. I took the car back to Firestone and they told me I needed an ignition lock cylinder because the ignition parts had worn out. I didn’t get that part. The mechanic and the adviser concluded together for me to start the car with a screwdriver since using the key alone was an issue to start the car. I drove the car like this with starting it with a screwdriver for a few months but the car started acting hesitant and acting like it wanted to shut off when I slow down or stop. April 10, 2019 the car shut down when I made a stop. I had it towed to two Firestone’s and neither one of them could figure out the problem. They could not get the car started I had it towed to Mitsubishi and they installed a engine starting switch. The car is running. I got it out of the shop today. The car is acting like it wants to shut off when I slow down or stop. It is hesitant and weak. When I press the gas pedal after slowing down or stopping the car is dragging and acts like it doesn’t want to move forward. The service engine soon light is on and it hasn’t went off.