Please help my stepson

The profile picture is drawn by our boy. He drew this in June for his Nana's birthday.

I met my stepson four years ago when I married his Dad. He is an amazing kind hearted child, he's just different. At age 12 I taught him how to ride a bike and tie his laces. He is now 16 and now lives with us. He is in NCEA level 1 this year. He is half way through and does not have the number of credits he should by now, we are concerned he may not obtain enough as he currently has a total of 8. He is on a waiting list for the assessments and to get him help, he's been diagnosed with PTSD and now his father and I are trying to give him the best chance in life. He often crys because he doesn't understand himself and can't make friends. The money raised is to get my stepsons assessments done and get him the help he needs to succeed. We believe he is on the spectrum and we would like to pay privately to be tested as he will be in for a 12 month or longer wait to be assessed through the DHB. At the moment he is not getting any specialist care due to him not having a formal diagnosis. He's worth the world to me and has been let down on many avenues. As his step mum I have made sure he has seen doctors, dentists etc, now I need to help him understand who he is and work out how to help him learn so that he can have a bright future. We want to get him tested and help ASAP but don't have the money to make it happen. I don't want him to be another statistic.