Analysis of what am I?

No words are expressed when I come, eyes become gloomy, sunny days as it seems becomes rainy, a fullness beautiful day becomes a day of emptiness.

My presence changes everything in a split second, a day where everyone will think it will never end. In this world where nothing is certain, only I exist in the concept of certainty.

I am everywhere, I wander deep in the seas or as high as the skies, I travel through roads, I choose no one to visit either the Youngs or the old, I see everyone, I may be at your side or in your behind.

I was a result of a mistake from a bite of a fruit. I was never meant to be, never supposed to be, other people fear me and others accept me, I am the bad news mostly but beautifully despite all this I bring good news; that I am not the end.