It’s hardly a supernatural claim (though many religious folks do like it, and it is easy to pursue within many religious traditions. Said pursuit does not mean they successfully reach such a point though.) The meaning in your life can be completely chosen by you. ‘There is something worth doing, something worth thinking, and something worth living for’ along with ‘I am pursuing something like that’ combine for a very similar meaning as well.
This seems less like ‘meaning’ and more like ‘purpose’.
Obviously, I think you are utterly wrong. You must find something meaningful to have a purpose, but the purpose comes afterwards.
The linked article honestly seems like an article of faith amongst certain people. Meaning must not exist, [assume only material things exist, so anything nonmaterial must be false, even if it is blatantly obvious,] therefore, it doesn’t. [Value is a consequence of meaning. It isn’t the atoms that have value, but what they are at a more conceptual level.] It doesn’t try to justify itself in any way, so I see no reason to be swayed at all. It is also not true that you are automatically unworthy. You may be worthy, you may not be, either way, do your best [and thus become worthy -eventually.]
It seems as if you got the impression that the linked material was meant to be some sort of argument for my view; it was not. I only linked it because it contained some related, and relevant, ideas. (Though your aside about unspecified “nonmaterial” things being “blatantly obvious” intrigues me. Perhaps you might elaborate on what you refer to? Though of course this is tangential to the current topic.)
In any case, I am not sure what to do with the claim that “[y]ou must find something meaningful to have a purpose”. Is the sense of the word ‘meaning’ (or ‘meaningful’) here the same one as in claims like “People crave meaning”? Or is it a different usage? I can’t see any way to interpret this claim that would make it both true and non-vacuous. Perhaps I am not understanding what you’ve got in mind.