[Yonk]

So i have a 2013 320i with under 60,000miles on it. Just with in the last month i got a drive train malfunction that basically made me feel like i was driving a 2 cylinder moped. But the issue resolved (atleast I thought) by shutting it off and turning it back on the next day.

Took it too the bmw Nashville dealership and they didnt tell me **%^ other then the knock sensor may be failing but they are not sure could be bad gas. Nothing that really helped.
As time went on the Engine vibrated and shook worse and worse over time. Well i drove about a 200mile trip and once i got back off highway speeds down to stop light my car was shaking so bad i thought it was going to stall out.

As I accelerated it didnt seem like it wanted to shift automatically and downshift when coming to a stop. (Note it ran speeds up to 100-120 no problem) now the drive train came back, with a flickering off and on check engine light. The car idling is so rough that its shaking and im not going to drive it. Could anyone help with what it could be, i figured it could be honestly anything but i feel like a knocksensor wouldnt case this drastic of a scenario would it.

Also while accelerating there was this slight ticking noise as if metal was just tapping against each other. Im screwed lol