More scared of not existing than death itself...?

Currently having a wave of panic over this and need to just talk a little, thought this would be an okay place to do so.

I feel like the fear of dying is more common than what I experience and anyone I've really talked to about this doesn't feel how I do.

Ever since I was about 12 (25 now) I use to get panic attacks usually when I'm trying to sleep and my eyes are closed and theres nothing but darkness, because In my mind for some reason thats what happens after death or when the world ends. As if my consciousness is just floating around in nothing but darkness even though my consciousness would die too when I do. Im not scared of how I'll die if itll be quick or painful, I just want to continue existing as I am now. Anytime I have points of panic over dying its always me just imagining the world/earth being gone and being stuck alone in darkness. I guess this could be related to something else as well but its always in relation to thinking about death for me. Its just genuinely terrifying to me to know that I am going to be dead one day and I won't exist anymore.

Ive had panic attacks the past 4 nights over this, it usually isnt this bad I don't remember what triggered this. It just keeps coming up and I can't stop it.