At least it didn't end up like this:
Seriously though, it's always a good idea to ride as if you are invisible, as has been mentioned a bunch above me but I am just reiterating it.
Your situation is exactly why I ride with a camera now. It helps to document a situation so at least I can learn from it and perhaps help others learn as well. Your incident would be a good reminder for rural road riders to help point out that regardless how much traffic is on the road it is still possible you won't be seen.