9 year old with autism

hi

I am new to all of this and recently began to see a homeopathic doctor for my 9 year old son with moderate autism. Our biggest issues are his obsessions to do what he wants to do all day long. He gets these things stuck in his head and no matter if we are doing something fun he obsesses and gets upset about not doing what he wants. He currently wants to write pages and pages of stories and movies on hundreds of sheets of paper. He's a pretty healthy child with no known allergies. Born via c section. He had two ear infections as a child. He did have a reaction to the DTaP vaccine when he was 4. His arm swelled and became red. The strange thing is each time he gets sick the injection site swells like a tiny mosquito bite. He sweats a lot and has small white bumps on his cheeks that have been there for years. He's very strong willed and his default is to yell his responses when a demand is placed. He's constantly moving and constantly running a script of his songs and movie out loud. He hates flying insets and hates hair cuts and anything that requires someone to examine his body. He sleeps well but wakes early.
His current Dr recommended Sulfur. But he became even more agitated even at the lower doses and began having bathroom accidents. We stopped sulfur and recently began Thuja 6C and are not seeing any change. She recommended increasing to 12C. We are giving once a day.
i would greatly appreciate any advice!!

thank you!