Agression, Regression, C'mon Recoupment!!

I am currently struggling with my son who is severely autistic, non verbal,etc.. He is 7 years old and this last year has been horrible. He has become aggressive, and is hurting himself. We find that he is ok as long as we understand what he wants and needs or as long as he gets his way. His lack of communication skills as well as his OVERWHELMING need for sensory input are no doubt what triggers his violence. We are currently doing tons of therapy and are still trying to find a med to help him. any suggestions???