Former Theists, how do you avoid nihilism? eah, I feel you. But a pack of wolves has a certain cohesion. So maybe we're more complex wolves. We love and hate. We assert status with words. We're never done inventing ourselves or figuring out our place. Everyone cobbles together their own post-religion. Some go to more trouble articulating a philosophy or an anti-philosophy.
Even if everything is 'really' empty, our animal minds mostly distract us for this. If we do remember, then there are some twisted pleasures to be had. The individual is more godlike beneath an empty sky. — jellyfish
Maybe I'll be more descriptive in what the conceptual breakdown or deconstruction looks like in my mind.
The real muddle comes with the breakdown of the self.
I previously believed I was a soul made by God in his image who would live eternally.
I now believe that I am a biological process, who's primary driver is a brain. I am no means a coherent whole but rather a collection of competing desires, interests and emotions. These are ultimately the causal forces that result in my behaviour. And you can see the incoherence of this collection in the incoherence of my thoughts and behaviour.
And so when the brain described as "I" is faced with options it previously used reason to arrive a reasonable decision, relying on deep theistic structures to reason a way through. And I was pretty good at this kind of reasoning, a public speaker and debater who sometimes won!
But now I am a muddled mess, there is no underlying deep structures that the brain can rely on to reason its way out. There is no room left for "ought", just "is". I have recognized my brain to be the animal brain it always was. But the animal brain really ultimately only pursues self interest.
So I try to avoid those confused states, I practice mindfulness and stay in the moment and in the micro. But this doesn't leave one very engaged in a deep level in life. It's all just process, I am part of it, but it has no clear direction and no underlying principles. It's just random causality let loose.