The verse BG 2.12 is related to the Kaala chakra (Eternal Return).
Please refer this post:
When Brahma's day ends and a new day starts does the previous day repeat itself?.
The day/night of Brahma keeps repeating. Whichever events happen during that time, will also repeat infinitely.
We can also say that, "Never was a time, when you did not ask this Qn, I didn't answer and people didn't provide good comments. Never it cease to be."
Will I cease to exist in any state after death or moksha ?
After death, if desires are still there then we may get rebirth. If all desires are vanished, then the Moksha is attained.
After Moksha, there is no rebirth and hence the self is completely vanished to the point of no return. In other words, the self is merged with the supreme Self in oneness. Once a drop of water is poured in a sea, we cannot re-identify that drop back. It's gone.
In the next cycle, everything will repeat again. But since, all the cycles are perfectly identical, you or me won't remember anything until we reach again to this moment.
Refer this answer, which discusses life after Moksha & the cycles.