The reason you feel different on different days is because of your biological rhythm cycle.My wife used to keep a monthly chart on hers.

Ed L. wrote on 05/06/10 at 15:53:53:


Never have truer words been spoken!
This always helped me more than anything. In other words... Don't focus on where you're at, focus on where you wanna be. You don't look at your feet when you walk... Right??
Now get back on that horse!

You should not overextend your comfort zone on an unknown road..chances of straying into oncoming lane too great..and headon's on Bikes just don't get my vote.  The fear thing can come out of nowhere but usually it's something your mind catches below your consious level..and if your eyes are having trouble..well if you can't see clearly where your going (and this especially includes coners and uneven pavement) you'll go where you shouldn't.  As you have nnoted, it got better on subsequent rides..so carry on and have some fun.
As for the mechanics of turns, focus on the exit is great advice.  You should, on left handers for example, get to the right breaking as needed, drop or tilt to your left, accellerate out of the turn.  Or as my dear departed teacher told me, Break in, run out.  As you make your line through the curve, clipping the apex, and accelerating  out -you will be in more control and less likely be in the wrong part of the road.