Emotions all derive from whether or not we can fulfill the desires that we consciously or unconsciously set for ourselves. If you fulfill then you feel great. If you don't then you feel bad. The development of our capabilities to fulfill desires is the name of the game and that all comes down to making things personally possible.
You can read about why you hit a giant wall in this article:
Pinnacle Goal Setting Doesn’t Work
It will also direct to you a paper I wrote that will give you an ever deeper understanding of what's going on in your mind.
Hope it helps,
Nick