I have three manuscripts in various stages of revisions, and one I'm working on as a first draft. You may wonder why I don't just finish one manuscript and then go on to the next. Which would totally make sense. And sometimes, I wonder myself. But this isn't about second guessing myself and my work. It's about creating structure (which I shudder at), so I can take one step at a time to get to my goal, and be confident I'm going in the right direction.
I've worked out my To Do List and dates for what I'd like to accomplish with each of these manuscripts, into manageable chunks. My hope is this will help me focus on each step rather than being consumed with the Big Picture of a published book.
Be easy on yourself and make your goal attainable. Rather than being overwhelmed with your huge project, what can you do to break your goal into manageable chunks?