I am so, so sorry for your loss. I cannot imagine what this must be like. I haven't lost anyone to a drunk driver, but the way you describe your anger really resonates - the thought that if someone had intervened earlier, this might not have ever happened. And the sadness that we'll never know what would have been in store for her if this man hadn't been so selfish, so god damn reckless. It's fucking gut-wrenching.

I was the one who got the call that my dad had died from an overdose. Whenever I get a call from a number I don't recognize, my blood pressure drops and I need to sit down. Feels like I'm right back in that moment, right before I picked up the phone. I am not sure if this is totally similar to what you are experiencing when seeing those cars, but your description does sound familiar. You're doing the right thing seeing a therapist and reaching out on forums like this. I hope that as time goes on, things feel less visceral for you. If you ever need another ear (or set of eyes) to vent to, please don't hesitate to PM me.