A similar thing happened to one of my best friends almost exactly a year ago. A person stepped out in front of her car from a center divide and she hit and killed him before she even realized what happened. Her text to me, that i didn’t receive until the morning “I killed someone on the freeway” was chilling and i did everything i could to help her through it. I was so devastated for her, sometimes seemingly more than she was, and terrified that it would change her fun, carefree personality. Thankfully she made it through with friends and family support and, like you, faced no charges. She will never know why this man stepped in front of her car that night, and may never assuage the guilt associated with this experience, but hopefully it will continue to lessen with time and blur into the background.