dunno if it is near enough to be useful, but my fear of sleeping stemmed from having had to live with sexual predators as a child. when i was able to sleep at all, i often woke abruptly, hypervigilant and ready for battle.
i got past it by formalizing perimeter checks. when fear of predator attack was keeping me awake or i woke in that hypervigilant state, i ran perimeter checks on my quarters, actively looking for clear and present danger. after assuring myself i was safe, i plied grounding tools to calm the hyper-vigilance. i ran my perimeter checks as needed, comforting my inner child as i went. with consistency, the need began to fade. it's been a goodly while since i have experienced this psychoweird.
but that is me and every case is unique.
steadying support while you find what works for you.