When you say highway, just what kind of turns are we talking here? Are they sweepers or tight turns with 20 mph yellow triangle signs posted?
Anyway, best thing to do is just to ride to build up your confidence again. One thing to do is to scan the road way ahead for objects and those little piles of sand or wet spots. Take a late apex(
here's a page with diagrams) into the corner so you can see as much of the road up ahead as possible. It also gives you a better line into the corner, which makes evasive manuevers easier if there is that patch of sand in the road. Look through the turn, if you're not already doing it, and not on the pavement right in front of you. One thing you don't want to do is to decelerate all the way through the curve. You should be rolling on the throttle by the midpoint of the curve which helps you to maintain balance.
You don't have to lean over really far on our bikes to go quickly through the curves Our bikes easily take corners at 15 to 20 mph over those typical yellow signs without touching the pegs down.
