My son is being discriminated against in school for having bipolar and adhd what should I do?

My son is 10 years old and goes to school in a little town in Missouri. He was diagnosed at an early age with severe ADHD and has since been diagnosed with depression and Bipolar disorder. He takes strong narcotic medicine every morning. We have also just found out that he allergic to several foods and pretty much everything outside and is taking three types of allergy medicines every morning. He makes good grades in school but has severe behavioral issues. He has trouble concentrating and can't sit still. He is unable to focus and has been given several lates which resulted in constant detentions after school. He had a couple of different outbursts do to his medicine not functioning properly and was suspended several times. I researched his disorders and took all of the doentation nto the principal. I have set down and had several meetings with the school counselor, the principal and the superintendent regarding my son and trying to come up with a plan to put into place. Nothing I have done has mattered because the school officials keep treating him like he is a problem rather than a little boy trying to get an education. His teacher this year even stated that she didn't like him and didn't want him in her cl. She repeatedly got in his face as did the counselor and when he would react or try to say something in his defense they punished him. Now because I vented my frustrations with several people in my life on Facebook the school took it as a threat towards them and involved the law enforcement and have now banned me from school property for a year which basically forces me to move my kids to a different school district. I am angry and upset for my son. I want to sue the school but need some input.