You should see a mental health professional who is familiar with adult Asperger’s Disorder. He or she should be able to clarify if you have this disorder and suggest ways to help you.
Wow. You do have a problem. And, I am afraid that you will not be able to explain to your aunt what her child is doing. Discuss your problems with your parents.
You need to consult with a knowledgeable SSI disability appeals lawyer concerning the possibility of filing an appeal of the denial of benefits for your child.