Work on a route that is not at your maximum ability. If you can lead 5.9 most of the time but not consistently complete, then get on a 5.6 which is well within your ability, gives you time to contemplate your surroundings, allows to you try holds and back off. Search for different holds. On many routes there are harder holds that can be tried, you can bypass the lower rated ones once you gain confidence. You don't have to climb at your max ability all the time, paricularly when leading. Good luck!