My 6 yr old autistic son non verbal with sensory perception disorder who cannot care for himself was denied disability?

My son is autistic severe, non verbal and sensory disorder, and I had to leave my career as a hygienist making 80,000 a year full time to care for him. I also developed anxiety disorder, adhd, panic attacks which prevent me from working as well. why would this be? This seems very strange. The man I spoke to said your son is disabled according to us so imagine my surprise when he was denied?
Thank you
Corinne