Help needed in finding a private ASD assessment for my son.

Hello all, for years I’ve known my son was different. It’s only since he started attending secondary school and me voicing my concerns that I’ve now had it confirmed by the Senco teachers at school that my son is displaying sighs of ASD. With the help of the Senco teachers at school we filled in questionnaires for CAMHS as my son was referred to them for an ASD assessment,to be told by CAMHS that my son doesn’t need an assessment but they could offer counselling. I was very upset but this as no one had met my son from CAMHS so how could they make this decision?! My son has trouble interacting at school and struggles everyday but CAMHS thought he’d be ok to sit in a room with a complete stranger and talk,no way!! So the reason why I’m here is to find help in getting a private assessment done as CAHMS are useless. I’d like to get assessment done so my son can start to understand why he’s different and for me to get the learning I need to help my son. If I don’t fight for what my son needs then no one else will....please if anyone can help us,we would both be very greatful. Thank you all for taking the time to read my post :)