My son was very poor at sleeping from the word go. He would squirm and thrash and arch his back. Yes he did have reflux too. He was also on a gluten, wheat, soy and dairy free diet. Still it continued and he was in my room where I shushed him all night and got up to him on times when shushing didn't work. He constantly sat up, lay down, rolled around, upside down, the whole works and into this he looked like he had had his head put in a bucket of water. The sweat poured fron his head.

He went to a sleep clinic but they didn't monitor him, I did a video of him out of frustration. Before I got to see the sleep clinic again at age 3 he started sleeping through. Not totally peacefully but great. Since then he goes to bed at 8, he tells me he is tired, goes to sleep fairly quickly and is there until half six. He is 5 now and only recently diagnosed. Think I fared well compared to some.
His brother (my son is adopted) is 3 and he is still as bad as your children. His carer is knackered and he is on melatonin too. He hasn't been diagnosed but I say he has it too.