Maybe you could have predicted that I would write on issues of cosmology and metaphysics in my academic career because of an experience that began as a child and has never receded.  Whenever I think of the beginning of time, the creation or Big Bang, or the concept of eternity, I get nauseous, for I am unable to conceive them.  I have genuinely been troubled by the questions why anything exists at all, but what would it mean if nothing existed.  Here comes the nausea.

Bulgakov addresses this issue in The Bride of the Lamb the best I've ever experienced:

Nothing is by no means like an ocean that flows around this being. Rather, it is divinity itself that is an ocean without any shores. . . .  Absolute nothing simply does not exist; it is a "conditioned reflex" of our thought, not more. . . .   It is impossible to imagine that, before creation, there "was" a nothing that was like a kind of emptiness, a sack into which, later, upon creation, all the forms of being were poured. . . .  One must include the world's creation in God's own life, coposit the creation with God's life, correlate God's world-creating act with the act of His self-determination.