Wow... what a relief? But it is also confusing.

A behavioural paed would be best. Also, while you are at it, google Temple Grandin's stuff... she has some youTube vids of her lectures where she describes the visual perception issues associated with ASD. OT and/or behavioural optomotrists help with that.

I know for me the first few months were the most confusing, and as you are going through MORE than just this, take it easy. Dedicate time for just investigating things. I spend 1 hour a week researching things associated with ASD and SPD. It takes time, but if I have it, I can spend it focused on that.