@PocketSand , your post about your son could have been written by my friend about her son. It really resonated with me.
He's autistic, has PTSD and terrible anxiety. He's got much worse over the last 5 years, since they had to move from a small social housing estate on the edge of a village to a flat on a rough estate in the middle of town, because of the "bedroom tax". He's been out of education since he was 11. She often has to cancel appointments etc because he's so frightened of being at home on his own.
I helped her get DLA for him, then PIP, and he gets UC with LCWRA in his own right. He uses his PIP to pay for counselling/psychotherapy that he couldn't get on the NHS and is finally starting to improve, to the point where she can sometimes leave him for a couple of hours. Caring for him has damaged her mental health, too.
He has been failed appallingly by "the system". He was on CAMHS waiting list for 5-6 years, but only had his autism assessment when he was almost over compulsory school age.
It makes me bloody angry that he's so much worse than he could have been because of the lack of MH input when he was younger, and his MH issues are much worse than they ought to be because of the delay in assessing and diagnosing him. And her own mental and physical health has suffered because of the strain of caring for him.
No child should have to wait so long for help for their mental health. Under-resourcing CAMHS is a false economy; there must be hundreds, maybe thousands of young people whose life chances have been ruined because of the failure to provide appropriate early intervention.
But hey, let's just make him get a job, and cut his benefits if he doesn't, eh?
I really hope you don't have similar difficulty in getting help for your child.