Unfortunate lecture subject

You know that moment when you realize nothing lasts forever, and that the whole concept of eternity can only truly exist as a concept. How can something fleeting like a human mind comprehend something unending, something that surely can not be proved. I mean not a single person will ever know eternity, we are not eternal. Well whenever that moment happens I think of the alternative, nonexistence and it makes me want to puke, luckily after seven years of hard work I have trained myself to not let my mind wander to these things, yet there is always one subject that starts me down the path of thinking about things that can not be thought about. The big bang, how the universe came into existence, how nothing became everything, the dawn of eternity, of existence. I hate it, I hate trying to remember what it was like to not exist in order to prepare myself for the future when I will no longer exist. It makes me sick, absolutely nauseous. My mind to small, my life to short. I will never be okay with no longer being alive.