My daughter went through a similar phase. She was in the 3rd grade. She was afraid she'd be the last one awake at night, topic of a show she watched without permission. She would lie awake at night and cry worried she would be the last one awake and something bad would happen. It lasted for MONTHS.
We tried many things. I had her think of happy thoughts to wipe out the scary ones. I would give her something to think about when the scary thoughts came into her head, like plan her next birthday party. I would help her get started. I promised to stop by before I went to sleep to check on her, and if she was still awake I'd stay. Usually she was asleep.
We had a talk about Jesus being with her, and had her practice the Lord's prayer when she got scared.
We talked with her pediatrician also, and the Dr. suggested making sure she was tired and ready to go to bed before getting in bed.
She eventually got past it, and we have a promise that she will not watch anything that she thinks will creep her out at night. She is now 13, and still does not watch scary movies.
Good luck.
I so am in the same boat!! My son is 7 and will not stay in his room to fall asleep. He gets out of his bed a minimum of 10 times and unless he can see me will not stay. I feel like I have taken everything away from him and he still does not care. I am at my wits end. I have to sit outside his bedroom door to make sure he stays in bed and if I attempt to get into the shower or go downstairs all hell breaks loose.
I have the answer! I had one child that couldn't separate. He was allowed to come into our room but had to sleep on the rug next to my bed. Sometimes I would offer my hand gentle into his as he fell asleep on the floor. Believe me, after about a month? He preferred his bed next to that rug..