Problem dealing with death as an atheist

[Zenith]

I am 100% convinced that when I die, there will be nothingness... no afterlife, no me, no thoughts, no blackness, no sleep, nor any ability to think.

Actually science has proven this to be true over and over again. The brain is dead, so you can think. When the brain is dead, you no longer have an idea of "self" or anything else. Your thoughts ARE your ego, your thoughts ARE electrochemical..once that reaction stops, there is no more YOU.

well, if a person is not only biological matter, but also something we call "soul", then this scientific discovery proves nothing: if the brain is dead, you can't prove there is no soul.

Science has also proven that life comes from lifeless particles. Life is made from DNA. DNA is composed of Hydrogen, Carbon, Oxygen, and Nitrogen. Four lifeless elements come together to create life.

The idea with the secret of life is not is not that people would disagree that a cell is formed of lifeless particles - no one disagrees with that (I guess). The idea is the thing that makes a cell function (i.e. live): is it only chemistry? is it physics laws? And what does it make the living cell cease to function? Can one revive a cell after it's dead for a day? if not, why (if the cell has every component there, what's wrong?)? How does a cell know what molecules to consume? Have you studied how the cell functions and can provide physical & chemical explanations that clarify absolutely everything?

I'm not a master in biology, so perhaps you know better something I don't.