Inspiration comes from so many sources. Music, other fiction, the non-fiction I read, TV shows, films, news reports, people I know, stories I hear, misheard words or lyrics, dreams... Motivation? The memory of the rush I get from a really good writing session - even on a bad day, I know I'll find that again if I keep going.
For me, I think one of the biggest battles is mentally. You have good days, and you have bad days. Randomly, you'll feel good for weeks, and then all of a sudden, you'll have a bad day where you're really sore. And you end up questioning yourself, like, 'Am I doing the right thing? Why is this so hard?'
Don't ever criticize yourself. Don't go around all day long thinking, 'I'm unattractive, I'm slow, I'm not as smart as my brother.' God wasn't having a bad day when he made you... If you don't love yourself in the right way, you can't love your neighbour. You can't be as good as you are supposed to be.