Out of curiosity, have you tried changing his diet? I've got a couple of friends with kids on the autism scale and they've had HUGE success with the GAPS diet (concurrently with enormous amounts of therapy). I've got my own issues with food intolerance and I go totally bonkers when I eat gluten, eggs, dairy or any kind of processed foods (my wife gets totally annoyed with me!). I'm heavily involved in Girl Guides and have seen kids react to food dye too (one girl went from absolutely uncontrollable to SO calm in a year once they figured out she was reacting to food dye!).
Good luck! I hope you find some relief and some sleep soon!!