Even though I have two three hour blocks per week that I keep for doing my writing and planning, I spend a good portion of that time faffing around on facebook, getting cups of tea and 'organising' myself.
The only reason I keep going is because I have a good grasp of the bigger picture of what I want to do, which is to have books in bookshops and people buying and reading them.
Sometimes it seems a bit daunting when I think the book has to be 60,000 words long and I'm only writing 1,500 per day at the most. But I'm getting better at dividing a big task into baby size steps and taking one step at a time until it's all done.
It also helps when you get beautiful copies of gorgeous books delivered to your door, which is what happened to me this week. You can say, "I did that," and feel a bit inspired to keep going.