I feel sad for you, my son is 11 and it is hard sometimes, I feel like his negative emotions are a reflection of my parenting skills. What has been helping me is the "Love & Logic" books and CD's I've been studying (I also took the classes when he was about 7 years old), He gets these bad cases of the wants, the gimmies and the sc%#ew You's. The techniques I've learned in love and logic has helped tremendously with my relationship with him and how to handle these moments, (which at this age seam all to often). Instead of telling him what to do, (I am learning real quick that I cant make him do anything) It teaches me to tell him what I will do (or will not do), example I'll say sweetly "I will continue to do the things I've been doing for you when I feel respected" Or This one worked great just the other night, he wanted me to take him to his friends house, I asked him to help me with the dishes after dinner but refused to help me clean up, I told him "no problem!" and dropped it, no more talking from me, which he's learning that when I say "no problem" The true message is "no problem for me, possible big problem for you", When I was done cleaning, he "demanded" I take him, I smiled and said, Oh bummer, I used all my energy cleaning and have no more to drive, he was so mad but realized later that he only could be mad at him self for making the decision to not help. Love & Logic makes me look forward to parenting rather than dread it. My favorite part is that, even if he doesnt learn the lesson (this time or ever), I get to keep my sanity, I dont allow my self to be walked on and I also find I dont have to yell, or lose my temper and add more destruction to the relationship, I get to be the loving parent and add peace to our home. It teaches me to not give him any reason to focus or be mad at me, to realize that its his decisions that cause him pain, not me that causes him pain. I just get to love him when he hurts and give empathy, (just as I would with a friend who made a bad decision, I dont criticize them nor do I fix there problem, I just be an empathetic friend to them and It works with him.
Here's the website (the parents section) if you want to check it out.
http://www.loveandlogic.com/parents.html
Good Luck to you.