Does he sleep better if he's in bed with you?
Just a thought - sometimes the more we try to pull away, the more they cling to us, you know? So if he's insecure about being alone at night and worried about you leaving (just a possibility), then insisting on leaving him in his bed may make it worse.
Talking about it is a great idea. It takes time for this to work, but it really can work well.
It goes against a lot of the advice, but sometimes engaging with them is effective. My DS always needed help to calm down and settle for sleep - sitting quietly and avoiding eye contact or not talking to him made him upset, but talking, singing and making him laugh helped him to sleep.
With any luck this phase will pass sooner than you fear. Really hope you get some rest again soon