Hey. You might have luck with a therapist who does applied behaviour analysis in particular.

I remember looking at some of their techniques and stuff and it looked quite good...

With respect to him not talking about his feelings... That might be because he isn't really sure how he needs / what he feels / what he wants.

One of the things I remember reading about was how often times when kids 'act up' they have a specific need and they don't know more appropriate ways of going about getting that need met. A behaviour therapist could talk to you and / or observe some interactions and they can assess what the likely needs are that the behaviour has become a way of getting...

Then they have techniques for gradually introducing new behaviours and not reinforcing old behaviours.

I don't know if this option would be available to you but it might be... Worth a shot. I've heard that they have fairly good success with things like disruptive classroom behaviours, for example.