I'm not worried about being a victim of some random mass shooting. I decided long ago I wasn't going to live in fear all the time.
I haven't changed my carrying habits at all. I rarely carry, and when I do it's a S&W J-frame in a pocket holster. If I want to go someplace that prohibits carry, then I go there and don't carry. I'm not going to live my whole life around carrying a pistol.
I am so much more likely to be killed in a car crash to and from work than encountering a deadly force scenario that to worry excessively about it is pointless.