I lost my 23 year old son

My name is jenn. My oldest son was killed in a motorcycle accident on june 30 2018. The man who hit him dragged him 132 feet before a woman got out of her car to tell him. Im so angry that this man didnt even get out of his car once he collided with my son and then decided he was going to drive home . i have two other boys 20 and 18 and i cant even imagine their pain. People say it will get better . i dont see how! I am so sorry for everyone loss.