i had a similar problem with DS and ended up ringing parent helpline. They wre great and told me to never let him in our bed, always trya nd start off the night in his bed. if he wont stay in his bed or wakes u during the night and wont go back to his bed, get a pillow and blanket and tell him that he either sleeps in his nice cosy bed or he can sleep on the floor in your room. Dont make the floor too comfy in your room otherwise you'll never get him out of there. I am thinking we might have to try this soon as what was working now is not...

Ringing the parent helpline and having a chat to them would do wonders i reckon, GL