Worth

I can't understand this thing about worth and value; why do I have this belief that out of all of the 2 or 3 billion human beings, only a certain amount of them have value, and the rest, including me, haven't?
I was thinking about it yesterday, and that realisation came to my head.
Why would I think that I don't have value, as well as why other people wouldn't have value neither, and why the ones who had value have it, why can't all humans have value?
But then, how could all the human beings HAVE value? Is there enough value in the world for each, each of us to have value? Is it possible?

When I think of diamonds, maybe there are 3 billion diamonds in the crust of the earth, scattered everywhere. DOes it mean that some diamonds would have more value than the others, and some would be less valuable? Who would judge of that anyway, other than a human being?

To a god, maybe the brownest, crappiest looking diamond is immensely more valuable than the biggest, clearest and with most "carats" or however it is measured, diamond which to a human being would be the most valuable, but to a God would be less interesting, or maybe it would be as equally interesting.

I really, really, really struggle with self-value.

I don't see why I should be worthless, but I feel it. I am not doing poor-me, but just expressing how I feel. No need to pity.
I just need to understand all this.
Why do I think that way.

It is a shame that a human head isn't like a computer.