"Wherever you go, there you are." The philosophy of the "Geographical Solution" to problem solving. The issues come right along with you, of course.

I think this is about him and his inner world and his fears, so changing anything outside of him is only going to change things outside of him. At the new school he will still be him. And changing schools could serve to reinforce things like * someone or something outside of him can change how he feels inside, * there is something 'wrong' with him that he can't attend a school many others attend and in which they thrive, * there is something unacceptable about having troubling feelings that the person should hide or be hidden away, * problems should be avoided instead of dealt with directly, etc.

Stay put if you can, and find a therapist for you and for him.