I too had that same emptiness when I realised that all religion was a sham, but then I started to learn about the human brain and how its design presents a duality of mind that can be mistaken for god.
Also how we can't help seeing patterns in chaos (apophenia), and then trying to make sense from those "patterns". Then, I started to think about the universe outside of religion and god, and realised how amazing it is; and how beautiful that a myriad of chances had created a set of conscious minds that were sophisticated enough to contemplate their very origins.
Thoughts like these fill the emptiness, to know that I am alive in a very narrow timeslice of the universe, whereby it is able to support complex life.
Nowadays I don't feel empty, because I've shaken off the anthropomorphic illusions of religion, and that's just great :-D
Cg