Check Engine Light On problems of the 2015 Hyundai Accent

While driving on the interstate, car decelerated and would not go past 5 mph. Had to get it towed. Throttle body replaced and now needs the the catalyt converter replaced in which I do not have the funds. There is an ongoing "ticking/clicking" sound in the engine, check engine light is currently on. While driving and coming to a red light, the car engine revved and the car started accelerating even though my foot was firmly on the brake. Car made a jerking move so I threw the gear into n and then park to stop the revving. Car is currently parked.

At first in the beginning my car does it once in a blue moon; however now everyday for the past two months my car would power down while being at a red light, stop sign, or in motion. When it powers down the engine and battery lights comes on. I would have to put the car in park and restart my car. It normally does it twice everyday. This is a safety hazard for myself and my baby. I'm scared that a car would come up behind and hit me while my baby is in the car. I fear our lives. When I took it to autozone for them to check and see why my check engine light was on the code was always catalytic converter. I went to go get that fix and my car is still having the same problem. Also, when my car is in motion the rpm doesn't move it stays at 0. Also, the sensor for the passenger air bag isn't working. When somebody is sitting on the passenger side the airbag light is off, but when somebody isn't sitting there the airbag light is on. I haven't been in any accidents.