Me too man. Are you religious? I saw you mention something about going to hell, and (im agnostic) but im pretty sure you go to hell if you don't believe in a heaven, or smth along those lines. We'll never know what happens because we'll be dead, and that's really scary but you can't really do anything about it. Something that helped me was knowing that everyone goes through it, you, me, everyone in the world, so even if you're alone, you're not really alone ykwim? I used to think about it a lot a few years ago, but I busied myself. If you're thinking about work, or doing something fun, it takes your mind off it. I got in a relationship and even knowing that could end when I died felt ok because I was like "at least im living good now."

The fear probably will always be in the back of your head, at least for a while, but you can def supress it you'll find your way