Not everyone is privileged enough to do what you love for a living. Even if you are chasing your dreams and following your passions, there will still be tasks you're not fond of doing. In either case, focus more on the work that you actually enjoy doing.
"The pressure of being required to sit at your desk until a certain time creates a factory-like culture that ignores a few basic laws of idea generation and human nature: (1) When the brain is tired, it doesn't work well, (2) Idea generation happens on its own terms, (3) When you feel forced to execute beyond your capacity, you begin to hate what you are doing."
The team over at Mind Tools state that we're more effective at work when we have a "positive attitude."
"People with a good attitude take the initiative whenever they can. They willingly help a colleague in need, they pick up the slack when someone is off sick, and they make sure that their work is done to the highest standards."
Want to the secret of getting more done? Reduce the amount of decisions you have to make throughout the day. That's why Mark Zuckerberg wore that same outfit for years. Most days he still does. It prevented fatigue. I will say though, I tried this and it was hard on my relationship with my wife. Make sure you find your balance.