Move to safety first and call 911 for an official police report. Always get a...

https://dlf-ne.org/what-if-the-other-driver-changes-their-story-later-a-paralegals-guide-to-protecting-your-claim/

Move to safety first and call 911 for an official police report. Always get a medical check, even if you feel fine. Take plenty of photos and collect witness names right away. Keep your statements brief and never admit fault at the scene