Along with what everyone else has said, I would encourage you to read up on Pathological Demand Avoidance. It's an autism profile that's getting a lot of attention (and funding!) in the UK but isn't used here because its not in the DSM-V (the big book of psychiatric problems kids can be diagnosed with and the codes that go with them -- no code, no dx). I just happened to stumble across it one time, and my first thought was "This explains EVERYTHING!" Everybody who worked with him had the same reaction.

It answered a lot of questions, because PDA includes some behaviors that would be atypical for other autism profiles. And it renders ABA, the therapy of choice for "normal" autism, useless.

I'm not saying that I think your child fits the PDA profile, but in my journey with my son, I've found that understanding even the things that can be ruled out can be helpful.