I have had only one occasion when I lost traction around a tight corner. It was my rear wheel breaking loose. It really made my heart skip several beats.

But almost always, when I think I can't go around the corner any faster because I'll lose traction, I'm not even close to losing it. meaning I'm a chicken. I think most of us are. Ride with an experience crit rider and have him/her pace you through the turns at high speed so you'll develop more confidence. And practice as others have said.