I was in this position for many years. It is absolutely and totally soul destroying so I know how you feel. I wish I had had this thread to help me , God knows I tried everything I could think of and there was nowhere to turn. Doctor was useless, everyone I tried was useless. Therapists let my son down or didn’t help. He was desperate for help and couldn’t find it.
Amazingly , he is now living in a shared flat and has a full time job, but the price we have had to pay is he’s cut the whole family off. I don’t know which situation is worse. Heartbreak either way.
I suggest small steps. Can your son volunteer doing something to give him some sense of agency and self esteem? A charity shop, animal shelter, gardening initiative? That would help him meet people and learn some skills at least. Does he do his own washing? Can he cook? Teach him these skills. Teach him to clean the house and get him cleaning for you so he’s contributing. Ask him to sweep up leaves, go to the shop to get some milk, little things. Set him small targets.
What would support him to engage with social services? Can you be there with him, fill in the forms with him, talk to him about his anxieties? He is most likely overwhelmed with fear and like a cornered animal . Think of strategies to help him deal with this overwhelm.
it’s so important that he doesn’t just fester in his room. Would he join a gym , a walking group, a film club?
Most importantly look after yourself because the consequences to your health and wellbeing are enormous . Find whatever way you can to support your own mental and physical health. What is his father doing? Does he have siblings?
Also consider carers organisations who may be able to offer you help and support. I went on breaks with them which gave me the chance to talk to other parents in a similar situation.