Cylinder #5 not firing plus stabilitrak is malfunctioning car is now undrivable

What is your question?

2016 LT2 6 cylinder, Issue was there when I bought the car 08/2019 the engine light was on and never went off, the dealer promised to fix it & gave me a fix it ticket at purchase to bring it back. I didn’t know a week later they would go out of business. It was drivable for a very long time the only thing was the car would shake badly when it was cold… if I turned it off and turned it back on it would reset the engine and it would run smoothly. At that time the computer said the 5th cylinder was not functioning. After awhile the stabilitrak light would come on and the car would shake violently, I would pull off the road turn it off and turn it on again and it would work perfectly again. In the past couple of months it no longer would reset and now it’s in un-drivable I can’t afford an expensive fix I’m retired and on a fixed income. Diamond Chevrolet should have respected my fix it ticket from my purchase no one told me the dealer was going out of business. I don’t know what the cost

What makes this problem better or worse?

For a Long time cold engine now all the time

How long has your 2016 Chevrolet Camaro had this problem?

Years