How do you cope with our inevitable deaths?

I've been struggling to sleep these past few weeks because I have a paranoid fear of dying in my sleep and I keep having existential breakdowns late at night which disrupt my sleep schedule. I find the notion that our consciousness is just shut off like a disconnected TV absolutely horrific. I don't know how to cope with that. It's horrific, I hate it, and nothing has value. Thr dissolution of the self is horrific anyway, I would prefer my consciousness is permanently trapped on my dead body than just not a thing anymore. I can't sleep, I can't do anything. Please help.