1spongemom,
Contact your district's special education coordinator, or the special education teacher in your son's school. Ask that a case study be opened for him. This will put into process whether or not to do an IEP or a 504 plan. Unfortunately, some schools will balk at this because of the money it costs to test a child. Sounds like your son's teachers are less than understanding which is just maddening. Don't give up. Lots of kids learn coping skills to manage their anxiety in school and overcome their problems.