"Happiness is that state of consciousness which proceeds from the achievement of one's values." [Galt's speech in Atlas Shrugged]
Objectivism should not be confused with hedonism. It does not say: "do whatever feels good". Even saying "do whatever makes you happy" can be misleading. Rather: discover what your true values are across the long-range span of your life, and strive to achieve them. In doing so, you will be happy.