Antagonists, internal and exterior, sabotage the protagonist from reaching her goals. The very same antagonists plague the writer as well.
In the Middle, the writer begins to doubt herself. Her way becomes murky. She looks to others for validation. Old beliefs of not being smart enough, good enough, or productive enough turn from a murmur to a roar. She rails against never receiving the credit she believes she is due. Accepts all the old criticisms she throws at herself. She fears. She falters. Her passion for her project wanes. The antagonists begin to win.
Rise up out of the lower energy systems and move to the "third eye", the place of wisdom -- of intuition.
Listen, not with your mind or through your ego, but to that deeper voice. Make time for yourself. Partner with the process. Pull your protagonist and yourself through the slog and toward the Climax. See your way clear.