Help for my teen son??

My son is 14 years old and has ADHD. He's very impulsive and has dyslexia as well as auditory processing disorder (what he hears isnt what is being said- at least not in the same order). He went to speech therapy when he was in 1st-3rd grade for the auditory processiong disorder and he's medicated for his ADHD. He was doing well at his school but we moved so he had to move schools. His new school is not at all sympthetic to his needs. He's been suspended 3 times because he's been disruptive in the clroom. His dad went to school with him one day and followed him around. We learned that one of his teachers is always fussing at him- even when he's being quiet. Now, he's on the brink of not ping 8th grade because of the difficult time he's having. Any ideas? We've grounded him, taken away his video games and TV, etc. We have 2 girls who are doing great in school. Also, my son is a great person. He's very talented musically. He's becoming depressed and I worry alot about him. Ideas?