Awww man, my heart just sunk for you and your son.
I don't have any advise for you

, sorry. I am going through something very similar with my youngest son and I am at a loss. It really scares the heck out of me, not to mention feeling guilty like I may have handed him my biggest burden. Which of course I know isn't a healthy way of looking at it.
Anyways just wanted to let you know you've got company with this. You said you're speaking to the school nurse, I haven't spoken to anyone yet, sitting here contemplating what to do. I've already thought about meds and if I'd want to go there, it's really unnerving. I hope your app. goes well.
Wishing you and your son the best with this.