I wouldn't say my biggest fear is failure as I understand it's apart of life and is necessary in order to grow and be better. How you deal with failure is important.
Many of us when we fail we run away and give up. Instead we should be accepting our failure head on and trying again. Sometimes before we fail life gives us signs that what we're doing isn't a good choice, I know I ignore these signs as I'm someone who is very stubborn.
Let's not fear failure but be motivated by it, let us strive to be able and to not feel how we did when we failed.