Taking it too far

My head hurts from crying and being furious at the same time. My husband had a bad temper and im Always having to defend myself and our 2year old son from his rage but tonight he took things too far!!!! Tonight as he tried to "displine" our 2year old for "whining too much" (before i could stop him) he shoved our son so hard to the grown that my sons head slammed on the floor so hard! This happened right infront of my eyes!!!! I immediately got SOOOO FURIOUS i literally almost threw up i was so mad and so scared that my son might have gotten a concussion!!!!! I got into a huge fight with my husband!!! Idk what to do. I want to get a divorce. He could have killed him! Im an emotional wreck right now! Any advice! Or words of encouragement