As a teacher, I saw many parents move mountains if it meant their kid didn't have to suffer a setback or disappointment.
I totally get that amount of love and passion to want to protect the ones you love from pain and suffering.
The problem with that is that the lessons don't get learned and they are doomed to repeat these lessons with no understanding of how to effectively maneuver through the muck.
Failing or disappointment isn't necessarily a bad thing and it is definitely part of life. It is in facing these problems that we all develop the resiliency needed to face them again and again and again. Each time we do so, we grow stronger and better capable of bouncing back quickly.
I know it's hard, but let them fail, let them hurt, let them cry and be frustrated. Instead of running in to save them, teach them how to deal with those emotions.
When we teach kids to understand their emotions, talk about them, accept them and learn how to handle them, we are teaching a kid to SURVIVE and also to THRIVE!