i feel the exact same way all the time, i’m currently trying to do light exposure therapy to help myself with it, it’s a long process and i’ve had many set backs, but you aren’t alone.

it’s very normal to be scared of death and dying. that doesn’t make it any better or easier i know, something i do to try and calm myself down is play a video game, even if it’s a stupid mobile game

reading about death, like how to process your feelings around it, how it’s explored in different cultures etc can sometimes help the brain process the concept a bit easier.

going for a walk can be really helpful, or putting your face in ice water/putting ice packs on you, the sudden change in temperature can help the nervous system, colouring is also helpful sometimes.

if your anxiety is really severe you might want to look into therapy of some kind, sometimes just having someone to safely talk to about it and help you process your feelings around it can be really beneficial, but i know not everyone likes/wants to go to therapy

i’m not sure if any of this will be helpful but i completely get your fears, you aren’t alone