Why are you going back "before" time. Don't you realize that's a nonsensical concept?
Why do you need to consider that the Big Bang ends halfway through a cycle? Do you think time was linear during the Big Bang? It's not like you had space, and then a singularity, and then the BB happened.
It's like the Big Bang happened. There's no "and then". I realize it's difficult to wrap your mind around it, but we are not programmers of the universe and we cannot view it from a remote perspective though we pretend we can. Our thoughts are time based, we cannot think of anything that isn't also time based (except concepts).