Along with practicing the meditation and before falling into gap, you may notice a lot of thoughts coming from yourself, some are you do not want to face because they are too ugly and they represent too much of your ego. However you have to let them go through you. Just face the unwilling parts of yourself. Observe your dark side. Then when you exhale, gently push them aside and accept them as they are. Gently inhale and repeat your Primordial Sound innocently. So, you may be able to go to the next step, falling into your pure stillness.