Wait! Your entire premise is that the universe is infinite. Infinite means it has no boundaries. The very concepts of Beginning and End are boundaries. If you say that something is infinite, it means that it has neither physical *nor* temporal boundaries.
IOW, your claim is that, among other things, the universe always existed, that it has neither beginning nor end.
If it has no beginning, the universe could not have come from Nothing because the universe has always existed and it is made of Something; therefore *Something always existed*. This, in turn, means that Nothing never existed, and the entire concept disappears in a grammatical double-negative whirlpool.
This signature is intended to irritate people.