Time is just a dimension in the spacetime we live in which was created under the big bang, but so before that what would it mean for time not to exist?

Surely its not possible for something to come from nothing, so there was always something, although if theres no time the term always doesnt make sense? How could change even occour without time? How could the big bang be set in motion when motion occours over periods of time?

How can i exist? It simply cannot be, i dont see any way that the universe could exist or i could be experiencing this conciousness that i am
this shit is so fucked what the fuck man