21 year old son

I Have a 21 year old son who I am really concerned about.  He is working on our farm at present and cannot communicate with other members of staff and comes across as completely rude!!  He just mumbles most of his words  when he does communicate and gets angry very quickly, especially if he is asked to do something that is not within his work remit.  I have read through a lot of the autistic traits and he seems to have most of them!  I am in a difficult situation that not only is he 21 and difficult to communicate with but I am divorced from his father and re-married.  He lives with myself and my husband most of the time but I have no communication with his father, so no support to help him.  He has started doing a couple of delivery rounds for us (we sell eggs) and if there is a change in the delivery round he can’t cope, he comes across and rude and not interested and when he is not working he just shuts himself in his room. What can I do?