Nothing wrong with a little caution while descending, IMO. As fast as you are on the flats, who needs fast descending?

OTOH, if you insist on this mad quest you might try repeating the same downhill a few times or try following someone down who is a pretty good descender. On really long downhills, I found that you kind of slowly get used to the speed and let it go a little more over time, and then maybe more and so on. Familiarity with the pavement ahead and conditions is a good thing too.

One other thing- Whatever you can do to have confidence in your equipment... do it.