Oh dear Debra! As you say it seems to be a habit now which needs to be broken. My twins didn't have any sleeping problems (the odd bad dream and a definite denial of wanting to go sleep when they first go to bed though!! However my 10yo son shows OCD tendencies on occasion and he is very attention seeking (having twin sisters don't help) so if he gets into a habit it is very difficult to break.
All I can suggest is lots of reassurance before bed, going to him when he calls to let him know you are looking after him/are there, but not lying down - just sit with him till he calms down and then leave him to go back to sleep. He may get upset, but I would think you would just have to be strong and leave anyway. No matter how tired you are, I wouldn't lay down - that is giving in and this is a case of him having to learn to go back to sleep by himself.
Perhaps a night light would help. Maybe a couple of drops of Rescue Remedy (Bach flowers) in a little water (they are to calm and reassure and get used ALOT in our house!).
Hopefully a determined approach will break the cycle and once he has broken it once it just has to be reaffirmed that he can do it.
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