While you're going through this process of trying to find the satisfaction in your work, pretend you feel satisfied. Tell yourself you had a good day. Walk through the corridors with a smile rather than a scowl. Your positive energy will radiate. If you act like you're having fun, you'll find you are having fun.
Successful people maintain a positive focus in life no matter what is going on around them. They stay focused on their past successes rather than their past failures, and on the next action steps they need to take to get them closer to the fulfillment of their goals rather than all the other distractions that life presents to them.