My 9year old son

Hi I don't know were to start really well my son is 9 year old faces many difficulties.. My son has been out of school since back end of year 2 as he started running away from school then got to we're he wouldn't go in at all isolated his self we have got things In place he's just recently got ehcp and I'm hoping to eventually get him back to school which is goin to be a school kids with autism/adhd/learning difficulties anyway he has not been diagnosed yes so I came a cross a lady on Facebook she has 5 children and all autistic so I decided to message her which she messaged me back I went into very much detail about my son and how he is and she said its like describing her son to her anyway we spoke most of night threw messages so I carried our conversation and things I was saying she sent me a link about pathological demand avoidance and this describes my son so much in many ways IV never herd of this I'm just trying to get info so I'm clued up and I can put it to pediatrician as when we last saw her she wasn't much help I know my son is different he has been from really young but as u can imagine people blame parenting so I gave up untill 2/3 year ago anyway IV not give up I've been researching am not sure how much info I should put up but willing to answer any questions just wondering if anyone as or not been diagnosed thanx in advance..