I get passed that close several times a day on my commute, so for me, no big deal. If the OP is not used to it, then yes, it can be scary.

Big picture, what we do (cycling to work and back) is dangerous. Exactly how dangerous is somewhat beyond our control, but on the other side of the coin, there are lots of things we can do (as noted above) to improve our chances. From my perspective, this incident, no big deal.

In my experience the scary drivers are in Paris, where I was riding on PBP (in '91) and where instead of "Give Us 3 Feet" they would give us 4 mm!

Rick / OCRR