Hi Mommydear, I posted on this last week, as we are going through exactly the same! Sorry to hear you are struggling with it too.
My DS is 4 in Nov. and been having night-terrors for months now. He can wake several times a night - screaming out in panic, in a trance like state. Only mummy will do to soothe him back to sleep, so its quite exhausting.
He doesnt seem to recall the 'sessions' (for want of a better term) in the morning either. He has in the past told me, that there are things in his head, like the bad wolf or even a bear from the Goldilocks stories.
Ive tried everything for an easy wind down and to empty his head of stuff with nice stories, but just like our brains, he recalls events from the day or recent past which have been disturbing to him.
Like MalloryT, I reach for the matchsticks and get on with it. But it's not good, and all you want is for the poor might to have a restful good night sleep.
We do have night lights, well....twinkly pink stars which DS likes very much - he tells me. so when things get really bad, I switch those on (but DD shares a room at the mo, so can be difficult). But its not the 'dark' that wakes him, its the dreams.
Hope you get it sorted, but Im guessing that this is very common, and one mother of a wave we all have to surf!