Worried about my son

Hey 65 I know what you are feeling. I have 7 year old twin boys, one who is Autistic. He too is a picky eater. Like others have said, get to your children's doctor, if there is nothing physically wrong with him he will get hungry and eventually eat. But check anyway.
What types of support is there where you live?
Here in Southern Alberta there is lots of help for Autistic children. I would also suggest looking for local Autism support groups, you are not alone! These groups are parents just like you who want to help and who know where to go for help, use them.

Keep us posted, and in the mean time all I can say from experience is be patient with him and give him lots of love. I will be praying for you and yours.

Dorian