Chuck Wendig said that the secret of writing is to "write as much as you can, write as fast as you can, finish your shit, hit your deadlines, and try very hard not to suck." Let's go back a second. HIT YOUR DEADLINES. One of the secrets that I overlooked.
Part of why I'm feeling so energized about Ain't No Grave is that I see an end in sight. It's not the ultimate end, but it is the completion of one phase. Come hell or high water, I know I'll have the first draft in my hands on New Year's Day. From then on, it's a matter of revising and trying very hard not to suck. The ultimate deadline is one year. If the novel is not finished by October 2013, it will never be done. Period.
Without deadlines, you can go on working on a project without end, going nuts along the way as I did with the invasion story. I must have worked on that thing for two and a half or three years, all the while just going in circles.
Going crazy is a bad thing. Even the voices you hear in your head when you're a nut don't like you because you're such a basket case. Save your sanity, give yourself a realistic deadline, and stick with it.