You're viewing the cup that is life and death as half empty rather than half full. You're 15 years old living in a country with a life expectancy of 78.64 years. Death is not going to be at your doorsteps ringing the doorbell anytime soon, besides, when you are on your deathbed, the likeliness is that you'll be able to reflect on your past concluding that you've lived a thoroughly satisfying life. You're purely thinking irrationally as we all do, for irrational thinking is an intrinsic natural tendency. The afterlife is wishful thinking -- resorting to wishful thinking is a fallacious, cowardly and unwise move. It's much more favorable to live in reality than to persist in delusion.