Thanks for the response. I'm just perplexed by why all these head bumps/jolts produce headaches where I get the bump/jolt, and why this rear ending is resulting in a headache where I imagine the forces would be concentrated. The headache came on after I'd settled down and decided that this wasn't worth worrying about too. I'm exhausted from worrying about these bumps, and I think that's helped stop the amount that I do worry, but I'm poised to start taking Lexapro to help with the anxiety/depression. Hopefully it will do what it's supposed to and prevent me from ruminating on my situation.

It really was just an accident - a tricky intersection with a lot of traffic and I was trying to assess whether I could get over and the car in front of me slowed sooner than I was expecting. I haven't been concerned about my ability to drive (although I'll probably lay off it for a couple days!).