"Bouncing" is a good idea, keeps your body loose but attentive. Ready for anything, like a cat.
I don't have much fear on a bike, but I recognize the feeling from other sports. Another mind trick to accept and overcome fear is to try to get into the mindset where you *like* speed - tell yourself (even at low speeds) "whee! I love this! I love flying downhill! I'm superwoman! I'm <insert favourite sports hero> " It helps to sense and feel this enjoyment while you're still in full control, to get to that point of wanting to go a bit faster and test yourself just a little bit. You want that positive, daring feeling to counteract whatever old fears are holding you back.
Winter riding is much less about badassery and much more about bundle-uppery. - malkin
1995 Kona Cinder Cone commuterFrankenbike/SI SLR Lady Gel Flow
2008 white Nakamura Summit Custom mtb/Falcon X
2000 Schwinn Fastback Comp road bike/Jett
1998 Trek 6000 loaner mtb/Falcon X