My seven year old needs help... I am so lost.

I have posted a blog about this before and I think I got some great advice.  The thing is that I need it again.

My son will be 7 next week (day before Thanksgiving).  He has great qualities and I adore him.  At the same time, he is making my head spin because of his anger and aggression.

School started here in August and my little man has been suspended three (3) times this school year.  It is ALWAYS the same thing... he gets mad and hits someone or something (throws shoes, screams and yells, etc).  These fits last anywhere from twenty minutes to hours.  I am doing everything I can think to do... psychiatrists, psychologists, his pediatrician, counseling, etc.  I have not really had any luck other than ADHD.

They put him on Adderall and he became insane.  I mean... running down the halls in school saying he wants to kill people and that he is evil.  Well, we took him off of that and started Concerta today.  His teacher thinks that there is something else wrong (bi-polar) and that this medication is making it worse.  I can't get a straight answer from the doctors and they just keep changing his medication "until they find the right one".

Also, because of all of this his self esteem has dropped dramatically.  He honestly believes that he is bad and "that he sucks".  This is breaking my heart.

What do I do?