Both Tchaikovsky and Somerset Maugham are credited with saying “I write when inspiration strikes. Fortunately, it strikes every morning at 9:00 when I sit down at my desk.”
There’s an excellent book by Dr. Richard Wiseman, The As If Principle. Research shows that when we behave as if we believe something, we begin to believe it. When we behave as if we have a quality, we develop it.
Set a schedule you can keep, and keep it. It’s the single strongest way to build the writing habit.
Now, what most people do is go off and plan to write 3 hours a day, 7 days a week. That lasts about 4 minutes.
… more … “Building the Writing Habit”
I’ve been a web developer for almost 25 years, so this is not simply from the perspective of an author, though I have published 18 books so far and show no signs of stopping.
A longer diatribe about marketing your self-published book. This is a year-long class, which I’d be glad to give if y’all are interested. 
Authors who learn to love marketing will win in the long run. Marketing can feel like a slog through wet clay —wet clay flowing downhill, taking you with it. No matter what you do, how much time you spend in a million different social networks, nothing happens.