written at the low point of a vicious depressive episode
There is no heaven, no hell, no afterlife... at least of the kind which traditional religion teaches us to expect. You (i.e. your ego) will not survive this body, for exactly the same reason that your clock radio starts blinking 12:00 after being unplugged, or you have to back-up your hard drive. Data gets lost. Your body might be resurrected at the End of Time, but it might be like those heads in a jar in Futurama. The great Prophets weren't lying, as such, as much as trying to terrorise the simple folk into being good.
But you don't exist in this world, either. You - as an individual - are interpellated (as Althusser would have it) - called into existence - by the structures of this world. The twin traps of You are getting all wound up as to whether you win and lose the game of Who Dies With The Most Toys Wins; or the equal and opposite one, Who Dies With The Most Brownie Points Lives Forever In A Nice Place (And Whoever Gets A Negative Score Gets Fried Alive).
There's not much in Scientology that's worth it, but one exception is the concept of Eight Dynamics of the Self. That is: "self-interest" as defined by your personal biological unit is the smallest and lowest level of consciousness and responsibility. The next step up from that is your family and your domestic unit; up from that, the group (nation, class) you belong to; then humanity; then Life On Earth; then the physical universe; then as a Viewpoint detached from the physical universe (meta-consciousness, or as the vulgar would have it "the soul" or "spirit"); and past that, al-Haqq, the Absolute. The point being that anyone who puts their own personal identity at the top of their list of priorities is a really, really small creature, and due to be among the losers as everything they care about will cease to exist in less than 100 years.
The famous woman Sufi Rabi'a was seen running through the streets with a bucket of water to quench Hell, and a torch to burn down Heaven. Anyone who was motivated by Heaven or Hell, according to her, was as deluded and lost as anyone motivated by the riches of the Real World of Horrible Jobs (or, in her day, Goat Farming). The Absolute - the God's-eye view, or the view of the hardest of hard science - is the only thing worth worshipping. But all eight dynamics of the Self are worth living and dying for... in balance and moderation.
Whatever is really worth it about "you" is part of the Absolute, and is therefore eternal and immortal. Sadly, that doesn't mean what you call "yourself".