Accepting my son's autism

Accepting my son's autism was the most difficult yet the most important thing as I believe. I have accepted him as he is  and I’m trying my level best to get into his world and bring him to my world but there’s something that is weighing  my efforts, it's my failure to convince others to accept my son and his situation. Yes, some of them have accepted him in their own terms and they do advise me from their vantage point that we should plan another child who shall be there for my son when we are gone and many think we are wasting our time and money in vain.  Our whole world changed with my son.  The way other people view and regard to us. Some take it emotionally and don’t have courage to confront us. Some don’t know how to deal with it or some feel that we might envy their children or some are ashamed that there is someone not normal in their family and some try to point out one way or another who is to blame for the cause to my child's Autism from their point of view.  Due to these reasons as the years pass our friends and family members are getting further  and further away few remain who understands and supports us. This type of approach may depend on the society we live in, maybe we are unfortunate there as well.