6 years on and still not sleeping

[BettyBoo246]

My 10 (nearly 11) ds has been scared of sleeping since he was 5 yo.
He is scared of anything and everything. He gets up every single night between 12 and 6 and dh has to go in his bed and sleep with him.
We have to give him melatonin to go sleep otherwise he will take around 2 hours. Sometimes even the melatonin doesn't work.
We have seen a sleep consultant, doctors and a counsellor (10 sessions) none of which has helped.
He is waking our 5yo dd too screaming and crying in the middle of the night.
I have no idea what to do, I thought he would grow out of it but 6 years on we're still here. Its causing me and dh to argue and ds is constantly grumpy from lack of sleep.
Any help or advice greatly appreciated

Hypnotherapy?
No idea if it would work but might be worth a shot.

You may well have tried this, but would setting up a bed (mattress) in your bedroom for your son give him a safe space to come to in the middle of the night, with less disturbances for you and your husband? ie your son is the only one who moves in the middle of the night? I guess it depends if he's crying out in fright or for attention.

What time are you trying to get him to sleep? Does a later bedtime reduce the difficulty in falling asleep?

I have a teen who is a poor sleeper, but thankfully he will stay quietly (quiet-ish - I wouldn't want to share a room with him) in his room between about 11 and 6.

So he usually goes up around 8.30pm and I leave him at 9pm and he's pretty much asleep by then.
We did use to have a mattress in our room but he sort of "progressed" back to his room but would still come back in for dh. Its like he needs dh next to him in order for him to sleep. He doesn't want me or anyone else. We tried dd in his room but he still comes in for his dad.
He cant tell me what he's scared of as he doesn't know he just doesn't want to be on his own.
My dd is now starting to pick up on it and says its not fair he gets to sleep with daddy!
Last night was particularly bad. Me and dh aren't talking because of it today and ds is very very mardy and tired 😭