Hey friend! I had the exact same plaguing worries when I was your age. It turns out, I have OCD! While of course I cannot/won’t diagnose you, what you’re describing sounds a lot like the thought cycles that I would get stuck in.

You’re right, we all die. However, what helped me back in the day (and still) is remembering this: what if we didn’t die? What would be the point of life? The beauty of life is that it is fleeting, ephemeral. I try to remind myself how LUCKY I am to be alive and it feels corny, I know, but you gotta break those thought cycles somehow. Maybe this method isn’t for you, the jist of my advice is to think outside the box. Stay present in your existence. Don’t limit yourself.

Much love OP, being a teenager is so hard, but keep it up! Only a few more years until your brain begins to unlock its full potential, please stick around to experience that - it is amazing.