A certain amount of fear is beneficial. I would actually be more worried if your arousal level descending a hill is similar to that of taking a morning piss. Too much fear, of course, can be crippling. That's why I think you should work on hills that are manageable. Just keep in mind that too relaxed is the same as letting your guard down - which you should never ever do.

Some people simply like descending more. Maybe it's the adrenaline...god only knows I'm a junkie...

You might want to include at least one manageable descent per ride. This way, the experience will feel less foreign. And when I say manageable, it should be just challenging enough that you're in that area between crippling fear and trivial boredom.

Don't get tunnel visioned. Use your peripheral vision to watch for obstacles. For example, when descending Suncrest, I have to keep an eye out for deer crossing the road.

Be sure to look far enough ahead to pick a primary line AND a secondary line. The secondary line will give a back up plan if for any reason the primary line won't work. Also listen closely for any mechanical troubles; I've done some descents in which the split-second warning of a hissing tire was JUST enough for me to brace for the subsequent wobble.

You're probably over braking. Remember - you can raise your upper body just enough to create an air brake and lower the body to increase speed.

Be sure to give plenty of room to your fellow riders. If you're in the slipstream of another rider and that rider isn't pedaling because the hill is too steep or he doesn't feel like it, you WILL move closer to him. And when that happens, a panic over-grab of the brakes will scrub too much speed.

You'll have to figure out the idea spot in your particular group. For starters, you may want to stay towards the back; this will allow you see the lines others take; it will also give a good reference for the speed at which you should descend. If it's any consolation, time lost on descents are usually not as great as that on climbs. It's not so tragic if you're the last one down the hill (and, if it is to you, all the more reason to practice regularly).

I don't know if you work on your own bike. I do and this gives me absolute confidence in its ability to function properly. I also use first rate components and I'll retire any component if I even suspect it's been compromised; hell, I'll retire some components such as handlebars after a few seasons (even 7 series aluminum bars that I use can fail from fatigue).

If you don't wrench your own bike (or if you have questionable skills), find a mechanic that you can trust; he should be your new best friend.

Any doubt in your equipment at the start of the descent will only fester as your gain speed. This, in turn, will create more anxiety every single time you even think about descending.