What was the hardest thing you had ever fixed?
The hardest think I ever fixed was trust in others. With that being said, it took a choice to believe in someone bigger, than me and to understand the truth of unconditional love. This creates an environment for my faith to heal the mistrust that was in my heart.
To fix something there has to be knowledge in whatever is needing to be fixed. By fixing something emotional you have to be taught what the root of the problem is, then seek education for it, then making a choice to let the problem be healed. Fixing an emotional issue can take time. So one key component to fixing it is patience.
I am certain you were not looking for an emotional example of the question you asked. However, being a guy dealing with emotional issues is difficult for us, because often times emotions are not logical. However, this is an issue that can be fixed within us, through the training we receive from faith.