I am so sorry to hear about your situation, struggle to get proper medical care for your son and your family's financial difficulties.
I have a few suggestions to seeking financial assistance with your medical expenses
Nevada Department of Health and Human Services Division of Welfare and Supportive Services
Nevada County Health & Human Services Agency
Your church or local community charities for financial assistance opportunities or organizing a fund raiser to help your family
Has your son applied for Medicaid-since he is disabled and unable to be employed?