When you die you literally cease to exist. There isn't anything.

You don't feel pain, you don't feel happiness. You just stop.

You're not even aware that you're dead, because you've stopped working.

There is no blackness because blackness implies you can take in the blackness. There is nothing. You don't exist.

It's not even a void, you just aren't.

Your brain stops, your consciousness stops, you're over. The end.

Mark Twain: "I was dead for millions of years before I was born and it never inconvenienced me a bit."