My 5 yr old DS has AS and has just got a proposed statement through offering 34 hours a week 1:1 with a teaching assistant (we are asking for placement in an ASD unit at another school, though, so the panel are reconvening on Friday to make a decision on this!).
I'm really sorry you've had such problems with getting your son seen by professionals. Unfortunately, if there is one thing I have learned from this arduous process it is not to rely on or take at face value anything any 'professional' says. This is not because they are all evil bastards conspiring aginst you 9although some of them may be ) but because (as is often the mantra on the MN SN boards!) - you are your child's best (and often only) advocate.
In our case, it was about 15 months from me getting a GP to agree to refer to a Paed to us getting a diagnosis and the LA agreeing to assess. The diagnosis was the really tricky bit for us, as he seemed to be batted back and forth by the health professionals for months before anyone would actually dare to mention ASD. In that time, he was seen by CAMHS and a SALT, and his school got a lot of advice from advisory teachers from a local special school, an OT and various other professionals from the LEA. Unfortunately, for us, it had to get to crisis point (repeated exclusions from school) before the LEA fully came on board.
When I made the application for SA I went completely OTT, wrote a hugely lengthy piece of parental advice and copied in reports etc. This was just at the rquest stage.
I also got hold (ah, google!) of email addresses for all relevant professionals and completely invaded their professional privacy (you know how they hate email contact). I wrote repeated updates on how poorly DS was doing at school and how desperately he needed the statement and cc'd everyone and their dog in. I also phoned and cried and cajoled to get him bumped up waiting lists, so that he had seen everyone he needed to see by the time SA was carried out.
It was exhausting and, at times, my mental health probably suffered (the rest of my life certainly did - I had to take huge amounts of time off from my university course and defer exams etc).
When they agreed to carry out an SA, I didn't leave a thing to chance. I insisted on meeting the LEA Ed Psych before she saw my son to advice her on our perspective on things. I emailed the Paed to try to impress on her the fact that the statement was crucial and that her medical advice must reflect this. I copied in every report, meeting minutes, letter etc that I had and wrote a 16 page parental advice.
Madness.
It worked, though.
I would be more than happy to advice you on anything you aren't sure of. Our LEA is notoriously tight with statements, and I learned pretty quicklly that i would have to pull out every stop and try every trick in the book to get what I believe my son needs and deserves, even if it makes me look like a crazy lady...