There are many books about achieving success, none about achieving failure. Nobody likes to fail, everybody wants to succeed.
Yet failure goes hand in hand with success, just like the yang cannot be separated from the ying.
Once you accept that things "might not work", you've made a major step in the right direction. The myth of overnight success is just that - a myth.
Failure is not the end. It's a step towards success.
By not giving up, you end up succeeding.
So the more you fail, the more likely you are to succeed.