I can only imagine how scary it must be for you, your son, and your family.
For what it's worth, I think you're being a great mom right now by reaching out for help and doing whatever you can to support him. I'm confident both you and him will be okay in the end, especially since you're being so vigilant and caring. I'm also confident that your comfort provides him with a sense of safety and brings him at least some relief from the mental torture.
I wish you the best of luck. Let us know how things go. You deserve mom of the year award.