Certainly don’t look at the looooong history of religion. Folktales. Fairy tales. Legends. Philosophies. Nobody has ever thought about any of before you, just now.

you are not the only one.

No intrinsic meaning, to any of it. Most people in STEM realize that eventually.
Meaning is what we humans create because we need it, just like you say. Meaningful relationships, occasions, work, play, objects, locations, hobbies, etcetera. Only meaningful to (some) people. All meaning is 100 percent extrinsic.
There is no point, no purpose - it's what you make it.
You'll find some few who've come to terms with this, and grown to accept or even like it. And they have a way about them, maybe even a Reality Distortion Field (for the powerful ones). In their presence, you can believe amazing things.
You can find one like that, or become one yourself.
That last bit is really hard and painful. A different kind of adversity. Should you succeed, you'll become something like a magnet for others. Some of whom also seek meaning and context.
They won't necessarily know that. And you'll be more alone than ever, in some ways. Even in a crowd. But at least you won't be searching for meaning anymore.

Before i clued in that the Meaning of Life is a life of Meaning & What you give is what you get. So be of good cheer. Try always to give more than you take and before you know it, things will start coming round for you .............. a caveat tho: Discern who & where you give because it's no use 'casting our pearls to swine.' And that's nothing against swine ... it's just that they have no value or use for pearls.

The meaning of life is to live in the moment wherever that might be and be happy without judging your self because you are awesomely unique just as you are.

Well said.

The problem is knowing.

You're not the only one - you're not alone. We all struggle with that at some point. I hope you feel some relief from the sadness soon. It always helps me to listen to right kind of music, or to go for a walk in the forest. Even if it turns out that there is no real plan to life, there is beauty if you look for it. Best wishes to you.

Ah ha ... good one ! Suggest on-linesearch the word 'Gnostic' which translates 'Knowledge' ... the wisdom of knowing vs. the belief patterns of metaphors & fairytale religion.