Sadly, most medical professionals have been taught to do just that, "pigeonhole". When they can't do it, it seems only a rare few will continue to take the time to help you these days.

I echo strongly that this is an emotional and/or biophysical response to unmet needs or something aggravating in his environment. If either of you are able to take leave from work to help your son, he very desperately needs your care right now. Try to eliminate potential sources of toxicity in your home i.e. chemical cleaners, synthetic fragrances, etc. Eliminate processed/refined foods from his diet and use wholegrain foods. A highly trained nutritionist can be a wonderful support.

I am certainly no doctor but I used to work with children with developmental challenges and it sounds as though your son may experience something akin to Asperger's syndrome (essentially a very mild form of autism). Things like hypersensitivity to various situations, being "in his own world" alot of the time, and sudden outbursts of anger or aggression are typical. I'm the last one to put a stamp on something, but if you're looking for guidance in a general direction I'd send you wandering in that viscinity. He needs someone to reach out to him in what HE perceives to be a non-threatening way, so family is key. When professionals are involved, keep their numbers to a minimum so that he can develop somewhat of a relationship with them and avoid feeling like a science project.

I wish I could be more help.