Required Help on Autism. Own opinion!

My son 3 year of age and diagnosed with Mild  Autism he has speech but poor eye contact and respond when we call him once we came to know about his problem we have started his therapies also started homeopathy treatment 4 months back but we are still confused not much improvement seen yet and we are exploring best doctors for him but how to find every doctor has their own opinion regarding this since we have been taking homeopathy treatment for last 4 months doctor asked us to stop milk, sugar, gluten many restrictions on his diet my kid is frustrating too much he is under weight as well not improving his health too can anyone suggest me correct path because I am too much worried and do not know where to go for my child as his age is also growing up we are worried can anyone please give me a right direction or doctor for him my child also does too much humming