MasterOfNone, have you treated the anxiety through talk therapy/counseling alone?
If HSing isn't his first choice or yours, I'd probably seek to work on the anxiety outside school but leave him in place for now.
I've posted about anxiety meds elsewhere and won't repeat here except to say that for some kids it's a dramatic change for the better.
I can also recommend CBT as superior to talk therapy in our family's experience: it supports the person in taking control over their anxious thoughts and thinking more realistically.
HTH, hang in there,
DeeDee
