The next step is to forge your own meaning. It doesn't stop at "there is no meaning". Once you see the void you can also see that there is space to build and no zoning code to stop you. You can, must in fact, decide why you choose to live, why you choose to act and how you justify your actions. You are the ultimate and only authority.

That's really hard. We're used to always being able to lean on something outside ourselves for purpose and guidance. And, to some extent, you still can. Back when you believed in external, inate authorities you were choosing what you believed. Those powers, whatever they were, were never real. You were to some extent projecting your own beliefs, desires, and ideals on to those things; church, state, god, whatever.

Find those childlike beliefs and clean the ichor of false gods off of them. Look at them from every angle. Decide which ones to keep, which ones to discard, and what you need to build from scratch. Whatever you come up with, polish it until it shines. Like a blade.

Another suggestion; check out Buddhism. The Buddhists figured out the same premise from a different angle thousands of years ago. The more grounded, secular forms of buddhism have a lot to say about confronting the void of meaning and carrying on in the aftermath.