This is because you're running out of notes.
Here's what you do when you get stuck:
Kenneth Folk - How to deal with uncertaintyKeep noting but include more. Include "progress", "thinking", "equanimity", "soft place", "attention","analysis", "strategizing", "worry", "doubt", "questioning", "intention" (especially before an action), "imagining", "interest", "desire", "meditating", "fear", "disgust", "misery", "sadness", "anger", "aversion", . Basically anything you can note you don't have to cling to. The practice is about non-clinging. To try and "get somewhere" in meditation is a stumbling block we all find ourselves in. Keep noting through the roadblocks. Practice with the 4 foundations of mindfulness. There's tons of things you can note. It's easy to get stuck making a "conceptual noter-self" but there's more detail all the way up to vibrations. Keep zooming into what you think is a "you" and you won't find anything permanent.
As Jake mentions there are pitfalls with noting if it's too conceptual:
Gil Fronsdal - Noting