Not for a lack of trying, I assure you. It's just that no matter how hard I try, my mind won't accept it.
The thought of life and existence being ultimately meaningless (Something else my mind fights against, despite knowing it's true) is too much of a blow to my psyche to overcome and look at light-heartedly.
I'm just so desperate to have a purpose and meaning in my life, but at the same time I can't sincerely believe in any religion or afterlife. I try to "live in the moment" and "be happy and make others happy", but it just isn't enough. I need something more.
Edit: Thank you everyone for their responses so far, I do read them all. They give me something to ponder and think about, maybe even leading to a solution.
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.