What created the universe

I don't believe in god or the big bang. If the big bang created the universe, then what created the big bang? If particles created the big bang, where did those particles come from? It isn't possible for things to have always existed, but then again, it isn't possible for things to never have existed?

BQ. Is there an end of the universe? If there is, what is beyond that? It can't go on forever, but then again, there must be something beyond that.

It's perfectly OK to say "I don't know." We are pretty certain that the big bang occurred based on multiple observations from multiple disciplines. All of these observations come to the same conclusion, i.e. the universe is expanding and was much smaller and much hotter 13.7 billion years ago. The theory behind the big bang does not say anything at all about how it was initiated; it only addresses events that have occurred since the big bang. Most scientists will admit that they have no idea what occurred "before" the big bang (whatever that means).

Is there an end, what is beyond it, there must be something beyond that, etc. Don't know.

"No one knows how the first space, time, and matter arose. And scientists are grappling with even deeper questions. If there was nothing to begin with, then where did the laws of nature come from? How did the universe "know" how to proceed? And why do the laws of nature produce a universe that is so hospitable to life? As difficult as these questions are, scientists are attempting to address them with bold new ideas - and new experiments to test those ideas."

First of all, "God" is a man made fictional character that does not exist.

Secondably,
There are many theories of how our universe was created. One of my favorite is that two different universes had collided with each other, thus resulting in the Big Bang, and thus forming the universe in which we live in today.