Like I said, there's a LOT out there about writer's block. These posts address some common issues related to writer's block or they analyze the process.
Beth Revis addresses the age-old, impossible-to-really answer question: Where Do You Get Your Inspiration? Maybe her answers can help you.
Stuck In the Middle: the Novel Doctor is one of my favorite bloggers. He posted about that ever-present hump that seems to pop up around 40,000 words with every. Single. Book.
Joanna Penn's blog is also in my top 5 favorite writing blogs. Ask Your Inner Voice: How to Call on Your Muse Just When You Need Her. This post is thorough and organized.