I'm glad to meet you! I'm sorry you're having such serious issues now and so urgently need help. I wish I knew something helpful, but I will say that, for me, the "therapy" that I'm doing doesn't always seem to help right at first because I'm getting used to feeling something new, and that new thing sets off more defensiveness. Having said that, have you tried calling your OT? If your son is getting therapy now, they really should know that it is being very counterproductive for him right now. I know you don't want him to get dangerously unbalanced, especially since he's doing coping behaviors that can be physically damaging.

Please call your doctor and/or OT. At the very least, they should give you some coping strategies or some information to help, since they should know his specific needs. And be sure to have times, frequencies, good descriptions of behaviors. Hopefully, that will help them.