I'm really glad you're okay. I had a close call with a bus recently in similar circumstances and that's really scary.

If the roads you ride on are quiet, I might suggest, based on no documented evidence except my own experience, riding on the car lane rather than on the shoulder if you're riding at that speed, especially going downhill. It will protect you from cars coming out of driveways. There are also a lot more chances that you will be where the drivers of incoming cars are actually looking for traffic (fast traffic is not expected on the road side), and seeing you in the lane might impress in their minds the idea that you're going faster. Riding in the lane and being seen (coupled with wearing bright clothes) allows you, among other things, to send a STOP signal to the drivers (by extending your arm forward with your hand perpendicular to the ground, like a traffic cop). Most drivers react quite well to that and will usually stop, if only because that signal is quite universally understood to mean STOP. By the time they have thought about it, you're long gone. I think they'll be thankful that you took the decision for them when they see you flying by.

If cars are coming behind you while you're on their lane, either they have ample space to pass you on the left, or you'll be gracious enough to move to the shoulder as soon as you hear them. When I do take the lane, I follow the trick given by some wise lady from TE, namely dividing the lane in three in my mind, and riding on the imaginary line between the middle third and the right-side third.

It was also a GREAT idea to scream at the top of your lungs. Not the time to be shy!!!

Keep the rubber side down, ride safely ladies!