From what I'm reading into your post, you planted the tree incorrectly. Check the link below to see if you did it correctly. Get rid of stakes, cut down on your watering, quit using the root stimulator unless it is a natural product like compost tea or seaweed extract (examples) & check the depth you planted the tree. Is the root flare exposed? I hope I am helping & not confusing you. Search this discussion board and the DirtDoctor website for additional help.
http://www.dirtdoctor.com/view_question.php?id=56