Gotta agree with SadieKate.
I have a friend who, well, when mountainbiking, used to call out "Pedal, pedal, pedal" and "Speed is your friend."
Speed puts the scary stuff behind you quicker, and on the downhill makes the next uphill easier.
You don't have to bomb down a hill doing a billion miles an hour, but as you get more comfy with the bike and how it behaves on the road, you'll get more comfortable expanding your limits.
Good luck and ...most importantly...have fun!