I had a crash a bit more than a week ago with a car that, thankfully, was relatively minor in the scheme of things and involved nothing more than some pretty serious road rash and a bruise to the forehead (even though I was wearing a helmet). I got back out as soon as I could because I didn't want my mind to make the fear bigger than it should be. There's obviously an element or risk in cycling and perhaps I didn't do a good enough job mitigating that by anticipating the potential action of the motorist who hit me. But other than do a better job with that and ride defensively, you just have to let the chips fall where they may.
The way I look at it, the health benefits I gain from cycling do far more for me than the likelihood of a serious injury from cycling.