Mother of autistic adult needing advice

My 31 year old son has just been told by his psychiatrist that he has ASD, but he still needs an official diagnosis. He came back to live with us 4 months ago with his girlfriend ,when work became overwhelming and he was in a bad place, self harming and thoughts of suicide. He is incredibly clever but interacting with people is a major anxiety for him. He resigned from his job which was a climbing instructor and route setter and is doing an accountancy course with the hope that he can find a job where he doesn't have to interact with people too much. His old employers wanted him to come back but his old job as head route setter has been given to someone else, he is finding it hard to accept this. The last few days he has been in turmoil and that's the way it always with with any decisions. I don't know how to help him and unfortunately have  developed anxiety problems myself. Do any parents have any advice? I just want to hug him  but that's a no no.