I noticed that I had posted on this awhile back. Now I can go downhill a little faster than before (30mph). Another cyclist told me to put your weight farther back on the saddle when going down a steep grade and that seems to help.

I actually go slower when the grade is very steep than when it is a little less formidable. When it's really steep (and curvy), I brake frequently. My hands tend to hurt from braking on these giant descents. I am not interested in missing a curve and flying over the bike or hitting a pothole.

When it's gentle and I can see where I am going, I can just enjoy the downhill without braking at all. Perhaps you can find some nice gentle downhill to practice on and start to conquer your fear.