When I am feeling that slog I turn to inspiration from creative sources outside of map making or worldbuilding. If I focus too much on maps and what other people are doing it may discourage me more than it motivates me. But if I watch a show like Chef's Table on Netflix which creatively tells the story of a chef and really the art behind their cooking...I really feed off their creativity and it inspires my own. It can be music, carving, bonsai, architecture, pretty much anything that requires creativity and motivates me. In fact, it's usually best if it's something I'm not skilled in.

Hope that helps!
- Josh