Desperate for support and advice

If anyone can suggest help or advice, any links where I can get support (explained below) I would be most grateful. I am at my wits end living with my son and my health is suffering badly.

My 21 year old son has Aspergers (he was diagnosed at 8 but has resolutely rejected this all of his life - and become angry and upset if there is any mention of it from anyone). On January 2nd this year, we had a row - which came out of my own exhaustion and sheer frustration with certain things he does (which would take too long to explain here) and I said certain things out of anger that I now deeply regret, but boiled over from years of swallowing my frustration at the way he leads his life and the way he sometimes treats me. I have been endlessly patient and supportive and positive, but this time, I felt furious with him. 

As a result, my son has not spoken to me since. her has no friends or acquaintances, and spends ALL of his days in his bedroom. He never goes out, never has anyone round, and never lets me in his room (this has been a major source of tension, as I need to access an upstairs room though his, and the house boiler, and he does not let me. He literally shuts the door in my face every time I try, and if I get angry or just firm, he just locks it and ignores me even more. He also has destroyed my important belongings (he smashed my computer with a hammer, losing so much precious work, records and memories) while I was at work, as 'revenge' on any argument I might have with him, so he holds my home hostage while I work non-stop as a struggling single parent to pay for everything. 

As he now does not talk to me at all, his life consists of his own thoughts alone, going round and round in his head, with no one to discuss of check on what he thinks (other some awful online world he might go to). He exists alone, and now without the only person on earth who cares and looks out for him (his mum died three years ago). I am desperately worried about him, but my own anxiety has started to cripple me, and for the first time in my life, I am struggling mentally to keep myself together and go to work. I am self-employed, so if I even miss one month of work, my rent would be unpaid and we would lose our home. Being self-employed means you get no support of benefits whatsoever, unless you completely abandon your employment (totally unfair but absolutely true). 

I really need to talk to anyone who has found themselves in anything like this situation. I need advice and help, as I cannot see any options when he is 100% non-compliant and in denial. I hate going home, as I have to deal with his ongoing rejection when I'm there, not knowing where this is leading. He never leaves his room and seems intent on cutting me off forever. He needs me and I need him, but I have no idea how to defuse this situation, as he is 100% single-minded when it comes to rejecting things without any visible concern. I am really terrified about where this is heading, and I need to find advice or help of some kind before I go under. All the help I have found so far is all about support for my child and how he needs to be part of the process, but my situation does not fit these approaches at all.