Your situation sounds almost exactly like ours.
In our case we had endless conflicts trying to get him to sleep on his own. Trying things like moving slightly further from the bed each night etc.
Nothing really worked. Ultimately we'd nearly always end up having to stay with him until he fell asleep anyway.
He eventually just grew out of it.
In hindsight, I ...
We found a great workbook thru our child psychologist, called
“What To Do When You Dread The Bed”
It really spoke my 9 year old, and i think it would still click with a mature 6 year old. It walked thru what fear are and used a lot of really relatable metaphor. It also has some in between steps to do as you transition him to independent sleep.
We too have a ...