Hello Geek – as Inky mentioned above, the Bhagavad Gita talks a LOT about 2 things: Dharma and Karma. Dharma refers to your noble mission, the inner guidance to do what you came on the planet to do. Does your newly discovered mission feel like you’re following the path of YOUR Purpose? The thing you came to the planet for? If so, don’t worry about happiness – what will come is fulfillment, a satisfaction of seeing your mission in action, a meaning to your life and living.

“It is better to live your own Dharma imperfectly, than to live an imitation of somebody else’s life with perfection.” -Bhagavad Gita
Also check out – 5 Paths to Discovering Your Dharma: http://www.mindbodygreen.com/0-16692/the-5-paths-to-discovering-your-dharma.html

As for some reading materials for accepting daily happiness, I recommend Byron Katie’s “Loving What Is”
And for more reading about Purpose, I loved “Callings: Finding and Following an Authentic Life,” by Gregg Levoy

I hope this helps.
Namaste, Saiisha