A Mental Squeeze Point is when your unsorted knowledge becomes so messy it overwhelms and discourages you. Either you are equipped with frameworks to overcome the squeeze point, or you are discouraged and possibly abandon your project. This is usually followed by yet another search for the next shiny thing to distract from the pain.
The Mental Squeeze Point is an emotion. It's something you feel, whether or not you're consciously aware of it. Try to be. Try to be aware of when you feel discouraged, or overwhelmed, or disappointed with yourself, or unhappy with your efforts. It's possible that's the form that the mental squeeze point has taken.
Perhaps the best way to overcome these squeeze points are to create a new safe space to assemble and organize the knowledge you're currently working on—before it completely overwhelms you. That dedicated space for thinking is called an MOC (Map of Content).
See: MOCs Overview