I would research the local homeschool community and see if perhaps you couldn't provide a better learning environment for him than the public school. It seems to me this might help alleviate his anxiety disorder if you can homeschool. My guess is the anxiety is only going to become more severe if you try to keep him in an environment that is not right for him. Moms know our children, their needs, their limitations, and their interests more than anyone...be his teacher and help him progress from where he is. Find local resources within the special needs community and homeschool community. You are not alone.