Melissa,
You may also want to post and get some advice on this through this website:
Attachment Disorder Support Group...message board:
http://www.syix.com/adsg/forums/adsg/disc1_frm.htm
Many people on this site have children with the same types of behaviors your four year old is experiencing. They also have had similar experiences as you have. (We have an adopted son who has similar behaviors to the point that he no longer lives with us.)
Good luck.
Linny