Night terror

Some nights when I am having a hard time falling asleep, I finally get there and I awake suddenly.  In that split second when I open my eyes in the dark of my room in the middle of the night I feel like I have seen and felt death.  I feel its nothingness, I see it’s darkness.  It scares me and I notice my heart is pounding and I remain spooked for several minutes before finally sleeping, like a baby.