Navigating PDA - safely

Hi

My son is 12 years old and was diagnosed with ASD with a PDA profile in May, 2024. He struggled in secondary school and hasn't been since May. He doesn't feel safe there so we have been working to see how we can have alternative education with his school. In the last few weeks we've reduced our demands on him as much as possible. His only friends are in gaming so we've let him play all day. If I suggest a short, 5 minute walk he becomes very angry and yells and it ends in tears. We're very close but he won't speak to me for days after. He is such a wonderful boy and I am heartbroken that he feels this much anxiety and that he sees even a request to brush his teeth as a threat. I want to help him in whatever way. I just worry that he is getting stuck in this world and it's not healthy for him. Even shutting off at night is upsetting enough so he often won't speak to me after. All his meals are in the playroom while he's on his playstation.

He can be the loveliest, sweetest and loving guy, but if there is any sort of demand at all on him - eg. shutting off after 10 hours on his playstation - it causes him so much distress. I worry about taking him to a counsellor or child psychiatrist  because it will upset him too much he won't benefit from it. He still doesn't understand autism and just sees it as a negative. If he thinks someone is dumb he'll call them autistic. 

Any advice is greatly appreciated.

Kind regards,