Your head starts to hurt when you think about these stuff is because early on aliens abducted the very early forms of life on this planet and planted something inside of it that would limit us from realizing the truth. What is the truth? I dont know, my head hurts
Nah, but seriously, you never actually cease to exist. You never stop living. Your brain may shut off, but parts of you go into the land, some into worms, etc etc. Those worms become a bird's food. That bird may feed you to its offspring, in which case youll turn into bird doodoo, and help grow natural resources, and those will be used for what not etc etc etc....
Im actually surprised at how incredible the idea of religion is. Its just a terrific concept. How many times have you "went to God" because you were in a tight spot? Its a place to go too, a person to speak to, pretty much a way out. My theory is that before they thought up of religion, the world and humans were corrupted. Thus we thought up of religion, and then we got to what we have today. There is no religion, there is no some higher power, and there is no magical place we go to when we die. Theres nature, and thats that.