I found this interesting article in Shape magazine (November 2016):
"Just telling yourself that you're capable of acing a challenge can help you nail it, according to a new study in Frontiers in Psychology. When people were asked by researchers to use a little positive self-talk during a competitive task- a brain game against an opponent they tended to do better. Emotions influence performance by giving us energy, which helps everything from running a race to a job interview, says the study's lead author, Andrew M. Lane. A simple "I can do it" is all it takes to find your edge."
Moral of the story- STAY POSITIVE! You can do it!!