Worried? Haha!
Ok. Try to picture this:
- At the bottom of things, it's probably all just energy.
- The elements our bodies consist of were cooked up either during the big bang some 14 billion years ago or in a supernova (our sun isn't hot enough for the most of them).
- Natural laws have a self-organizing, undirected characteristic to them (mathematical example: the mandelbrot set).
- If we direct Hubble at a small, apparently empty piece of sky for a couple of hours, billions of galaxies suddenly become visible, and the light of some of these galaxies was sent on its way up to some 14 billions of years ago, meaning that the source of this light is nowhere near anymore where it seems to be to us.
- We live on a small, not-so stable planet circling around a sun (try to find a realistically sized illustration) that will eventually blow up and consume our earth when it dies, but before that the Andromeda galaxy will collide with our milky way, but we're more than likely to kill ourselves long before any of that is going to take place.
- The atmosphere on the planet that actually allows for life is, in comparison, thinner than a layer paint on a pool ball .
- There are so many stars in the universe that the existence of some form of extraterrestrial life is basically a mathematical certainty. But at the same time, the distances between the stars is a barrier so vast that we basically can't even imagine a civilization advanced enough to overcome it... and if there were such a civilization: 1) finding us would be so improbable in that vastness that it can be assumed never to happen. 2) if they were to find us, consider this:
- The genome of our closest relatives, the chimps, matches ours by 99%. Now visualize the difference in culture and capability to think that 1% causes. NOW imagine the difference in culture and capability of a species 1% MORE evolved than us... See where I'm getting at? When's the last time we went looking for an ant with the intention to have a meaningful conversation?
- Dark matter and dark energy make up for about 80% or more of everything there is in the universe, but nobody has the slightest grasp on what these things are.
and so on, and so on, and so on. If that doesn't physically knock you off your feet, you're still in denial about it all.
Trying to paint a picture of the "reality" that surrounds us basically fries our brain. If we are humble enough to realize that we basically don't have a fraction of an inch of a chance to understand any of it, any speculation about an underlying principle of it all looses its emotional appeal. It's ridiculous!
And if on top of that, we realize that the odds of us existing are so absolutely ridiculously tiny considering the facts offered by the immense mixture of incredible knowledge we have amassed so far, then we can be simply grateful and experience a feeling of elevation whenever you wait for the bus and consider it all.
Looking at the sky and visualizing what we'd see if there was no atmosphere is enough for me to feel what others so desperately seek: The feeling some would call purpose (but it's not purpose, not a concept at all, it's just the feeling).
With that in mind, why would a "afterlife" or the absence thereof, even matter to you? We're staring at something so incredibly miraculous, we're experiencing something so vastly unlikely and we're free to explore it all in any way we wish with our body and mind that we're basically a lottery winner. What form would exchange this life for a winning lottery ticket of any kind?
Think of all the people that could've ever been born but weren't. We get to live. And we get to live in the most comfortable times of mindblowing progress and knowledge that ever were as far as we're aware. Why would then I be worried? Sounds absolutely ridiculous!
I listen to some Neil DeGrasse Tyson talks. I give myself a healthy dose of Lawrence Krauss.I have watched "The secret life of chaos" and "Hubble Deep Field: The most important image ever taken", learning about fusion and how the elements are formed. And so forth. At some point, you'll simply just surrender... and smile.

It's about the process and enjoying it. Clueless speculation about the nature of it all or worrying about what comes after just gives the ride a bitter aftertaste.
At the end, I don't need religion to give me a warm and fuzzy feeling, 'cause if I have a soul that exists, something called science has already saved it.