transitionsg from family bed- there is an attachment issue to consider

I am looking for advice and hope this is the group that can help. Background:I have a 6 year old son, who was adopted at 21.5 months from Guatemala. He was with a super foster family in Guatemala, but he never was alone- at all, including at night. At the one point, I found out he was in the parents' bed, even though he had a crib right next to their bed. When he came home, I did the absolutely worst thing possible and put him in his own crib in a room alone- it was a year long nightmare for us both. I never wanted to have a family bed, but I have ended up there. There was a point when he would go to sleep in his own bed, after the transition to a big boy bed, but it has be over 2 years since he has slept in his bed. he goes to sleep on the couch next to me and then I carry him into my bed. If I attempt to take him to his room, he immediately wakes up screaming. But now at age 6, I am really wanting my private space. I need the time in the evening when I have some seperation from him. BUT- he has been diagnosed with anxious attachment, so I am not sure how to go about this transition without taking majoy steps backward as he has made huge strides since last year when he started kindergarten. previously (3 years ago), I did the sitting in his room until he fell asleep. That worked until 2 am in the morning, then he was calling for me every 30 minutes, so he ended up in my bed just so I could get sleep. I don't have the 2 weeks off until November2012 where I could loose that much sleep again, but I can not go another year like this. There has to be a way for me to get back my bed and still have his attachment not be disrupted. Thanks so much in advance.