I would be getting him thoroughly checked out too.

Big hugs to you, I can't even imagine how you are feeling, especially with a baby to look after

Can you move him back into a cot? I tried Ash in the bed the other day and he wouldn't stay in it either. He normally goes straight to sleep at nap/bed time but he was up for 2 hours playing! I gave up on the bed idea and he can stay in the cot!

I think a main problem, which I am taking from your post, IS the inconsistency. Kids know that if they can push enough and get what they want that they will. He needs to NOT be allowed up to play. Otherwise it's kinda pointless sending him to bed in the first place, since he knows if he is difficult enough that he will be allowed to play.

Hope you get something sorted soon and get some rest!