The Gut and Psychology Syndrome (GAPS) protocol would really help your son. I can't recommend the book highly enough. The good thing is too that you heal through food so it doesn't have to cost very much, except the time to cook it. At the very least I'd recommend putting him on a gluten and dairy free diet and you should see such significant changes that it will make GAPS make sense.

Did he have antibiotics when he had tonsilitis? I would say his yeast issues have flared up and that is why his visions have become more aggressive.