What keeps you going isn't some fine destination but just the road you're on, and the fact that you know how to drive. You keep your eyes open, you see this damned-to-hell world you got born into, and you ask yourself, 'what life can i live that will let me breathe in & out and love somebody or something and not run off screaming into the woods?
I do object to the assumption that anything that might be outside of nature is ruled out of the conversation. That's an impoverished view of the kinds of questions we humans can ask, such as "why am i here?", "what happens after we die?", "is there a god?" if you refuse to acknowledge their appropriateness, you end up with a zero probability of god after examining the natural world because it doesn't convince you on a proof basis.