OK, will try and be brief but to the point I promise (even though I know it will still be long)but bit of background.
DS is 5 and in Reception. Attended the school nursery too.
Lost all words when small and has been under SALT since he was 2.
Language is now excellent - to the extreme, uses words other 4/5 year olds wouldn't understand etc - always in correct context.
Is a conformer and thinks everyone else should always do the right thing too.
Had issues n nursery, needing to sit in right place, correct lids not being on felt tips - everyone getting it wrong.
He controls all situations - poor eye contact, will completely blank people, not good socially at all, meltdowns, people always getting it wrong - shouldn't be talking to him etc etc. Doesn't like t be touched or people near him - now plays with a couple f children (I use this term loosley however) but tells me they never play the right game and they don't understand. He is def underachieving at school.
Had parents evening last week - teacher really annoys us, very patronising and doesn't know DS one little bit. However although they miss all the subtleties in school and have their heads in the clouds, she thinks he is seeming ok now - even after she admitted he still would never ever approach her if he had a problem, it's only if she notices/ All his work states refuses to use any tools/accept help offered - wants to work alone, still not using the toilets, no water bottle as it's a trigger etc etc.
EP has observed and totally believes us and sees some things but second observation she said he seemed quite relaxed - BUT she said still 100% belives what we say - socially he can be a nightmare, never wants to go to school, says school are getting it wrong as he is not happy - he (DS) has even requested to have another parents evening as he thinks it's a good idea he needs to tell them it all so that they belive it is true! EP assessed him and says functioning at about age 8.5 for understanding.
Woman from SALT who wrks alongside CAMHS observed and met with him (fortunately on not a great day for him) and agreed needs investigating, precocious speech, no eye contact - playing alone.
So, basically (sorry am getting there - still loads more I could say too sorry) at CAMHS on Thursday morning - first appt with them and am worried they will think I am mad and a crap mother as DS is appparently "fine" in school (he isn't as fine as she makes out but perhaps not socially as extreme as can be with us/outside). The EP has written how DS is classic child to present differently in diff situations and he needs understanding and that he is v intelligent. I asked teacher how he is doing academically and tbh she didn't know - she ummed and aahed and then said slowly he was above the national average but didn't stand out in any subject (thanks) this is the child that likes to discuss how the earth began and play draughts and chess - and one of his fave TV programmes is essentially anything with Brian Cox. So I know at the very least science and maths would stand out over literacy - and oddly his last IEP stated he was good in Maths.................(I hate her can you tell?)
So, what do I say on Thursday - he is well known to a few professionals now anyway - but his teacher comes across as all nicey nicey and nods her head a lot in the right places, but she STILL does not know my child and I feel the more I try and say, the madder I will seem :(
Teacher also told EP she had him in top group for reading due to him being very intelligent (his reading doe snot appear great tbh) but she told me he was border line and that the other groups are quite full 
sorry I'll stop and see what advice comes along..............