Question about guardianship!! Help!!

I have adopted a 13yo. It was a very complicated adoption. It took 3 years to adopt him. There were situations like sexually acting out with the foster children (although I still think that he was the victim), and he was in a residential treatment facility prior to my adopting him. He was just turned 11 when I met him in 2006. I was a licensed foster parent until the situation happened with the foster children in June 2007 just after the court order was signed on June 1 for the pre-adoption placement, the acting out situation happened within the week. I had 4 other boys then of similar age and younger. I only take boys between ages 5 and 12. After the foster kids were removed and the agency said that I can no longer foster or adopt younger children than him, I had decided to disrupt the adoption. I later decided to delay the adoption for 1 year pending more therapy. The adoption was finalized in Oct 2008. The problem is that since the situation in 2007, I feel that should have disrupted the adoption. I don't love him like I did then. I felt like I adopted him so that he would have a family, because no one else would want him. He has moderate ADHD, and ADD the meds don't seem to work. When he was in residential, he was on 6 meds, now, he is only on 3, and his behavior has gotten worse, and worse, and worse. His behaviors toward me has changed a whole lot. He is 2 grades behind in school, kicked out of school at least 3 times a month for fighting, hitting teachers, talking back to teachers, and just not doing his work in school, mostly talking to girls and disrupting class, and also walking out of class. He has changed schools twice. He has also have been jumped twice by kids that he started fights with at school. It is no better at home either, He has been very disrespectful to me, and he says that he never wanted to be adopted by me. He also refuses to use his new last name. He hates my 9yo Godson whom has seizures and visits me some weekends. He breaks things when he can't have his way, attempted to run away twice, says that this is his "fake family", and he can't wait until he turns 18. He is still in contact with his birth uncle, that was a promise I made when he was 11, also recommended by the adoption agency. I was wondering could I sign over guardianship to his birth uncle, who seems to have a better understanding with him than I do. He was originally going to adopt him, but he was in a bad situation at that time. His birth grandmother was also going to adopt him, but she was unaware of the situation that he was up for adoption and that she wouldn't be allowed to adopt him, because of being in contact with the birth mother. Presently, the birth mother is nowhere to be found. Now, I am wondering: Do I have the right to sign over guardianship to one of them (Uncle or Grandmother)? Will the court say that I have to have a suitable reason like: I am not able to take care of him? Could I just do a power of attorney delegating parental powers? (they have to be renewed every 6 months) I just don't want to go through the headache of an overturning of the adoption. There's got to be an easier way!! I'm afraid that he is going to wind up in juvenile or worse if continues to stay here. I can't take it anymore!! Advice please!! Please respond!! Thank you, garry9700