Parent of newly diagnosed 18 yr old

Hi

My daughter is nearly 18 diagnosed with high functiining Aspergers 6 months ago half way through first year of 6th form . It took ages to find out the root of her problems which only got acute in GCSEs. Because we didnt know why she behaved the way she did I think we just got less and less tolerant for a long time  so now we have a very poor relationship even though we now understand. She refuses to talk to me most of the time. I am worried she is depressed but she will not allow us to help and the gp says that is her right. We barely see her as she just goes to her room when she gets in from college and doesnt come down except for food.

She has always done well at school but A levels are challenging and her social life is narrowing. She was predicted to get As but is finding it tough and is  now stopping working right at the time it matters. This wouldnt be a problem for us if she just gave up, but she is obsessed with getting to Oxford University to do physics. She was encouraged to go for it by school but as she is now not working I dont think she will get in and the consequence of that  for her mental health due to her obsession  is frightening.

She has some counselling sessions with cahms but we don't know how these are going.

I just dont know how to help her we have had no support since the diagnosis and am hoping someone can suggest something.