I fell during a downhill turn at a speed about 40 km/hr because I didn't notice the side road was quite slippery (you know, the part out of sun shine). It's quite serious though I didn't know at that time and still had to continue the rest of the trip.

Of course, later I still remembered the feeling of falling but I tried to overcome my fear by practicing. Keep the speed low in the beginning and slowly increase the speed.

This article, Descending by Jobst Brandt, is also quite useful.