As you expressed, you see the task as "find meaning in yourself," a concept that can maybe be expressed as "meaning comes from within." This sounds nice! I think what OP was getting at is that this perspective has two problems: 1. It requires you to produce your own sense of "meaning" (whatever that means) that is self-satisfying, AND that works well in the society/community in which you exist; and 2. it is fundamentally self-centered. A hypothesis could be that this perspective seems to most frequently result in a failure to find "meaning" (probably better called "contentment") in anything.
As OP said, faith/religion traditions tend to hand you a set of pre-defined "here's what's meaningful" morals, and these also tend to be skewed towards group value instead of just self-satisfaction. When handed this outlook on meaning/morals, it seems possible there might be benefits - not having to come up with a self-fulfilling sense of meaning that also meshes with broader society, as well as a focus on being useful to the community instead of just yourself.
I personally find the whole "be yourself" / "do what you love" dogma-du-jour to be terrible, and prone to actually resulting in depression and shame. It is at the same time selfish, and self-sabotaging.
There lies the rub. What if you don't find anything to be meaningful to you. This implies that there are some activities that are inherently more meaningful that others and you just have to find them. Now you are back to square one.
Can it be rewritten to
> You can always find meaning in anything you do
This doesn't handwave the problem away. Main task is to find meaning in yourself not keep looking for activities that will give you meaning and hope you get lucky.