Essential nihilism is the idea (not belief) that reality came before you (or anyone else) and any idea that you hold as dear (or anyone else) and will continue on past you (and everyone else)

The universe came first and it has no meaning, no purpose

We exist by chance, biology and loads of mistakes. Biology has a reason; it is make more of the same thing you are

Now, if you choose, you can give yourself meaning. We are sentient, we can imagine a reason for ourselves, apply it and give it force

But there is no inherent meaning to any of this (sweeping hand gesture to everything about me)

And if I ever found evidence to refute this, it would break me.