What am I?

I am light
I am shade
I am the in-between
that comes
at sunrise
sunset
I am your agony
your pain
I am your salvation
your damnation
the one that will bring you down
I am your all
your only
your nothing
your refuse—
tossed aside
like rot
I am your threat
your comfort
I hold you close
embraced
I am your solitude
your escape—
I am