re: Opinion on why my pond is so muddy?

The water isn't turning over so it isn't clearing itself. When normal rain and runoff occurs again, it should start to clear itself. At this point the water is sitting in a big bowl, evaporating daily and concentrating the particulate, making it worse and worse each day.

The spring, by itself, should still have it at full pool and trickling through the spillway. But it isn't, so maybe it was a tiny little spring or maybe your spring got obstructed/collapsed in some way. Or your earthen dam is seeping.