How to cope with grandson

I'm a grandmother with a 9 year old grandson with Autism, ADHD, ODD, ASD coupled with sensory processing difficulties and motor coordination difficulties.  Recently he has become very challenging, and violent to his younger brother.  To see the evil in his eyes is just so upsetting.  He was a really loving little boy when he was younger, but now it is so difficult to cope with him.

Can anyone suggest where I can go to get help with knowing how to support him?