What is the ruling on vaginal discharge that is not felt to be released except during ablution (wudu') or prayer (salat), especially Fajr prayer, and does the ruling on سلس (incontinence) apply to it given the presence of scrupulosity (waswas)?

The cure for waswas (obsessive doubts) is to ignore it. If you are certain that discharges have occurred, your wudu' (ablution) is invalidated. If you are in doubt, the original state of purity remains. If you are unsure about the nature of the discharge, you may consider it whatever you wish. If the discharge of fluids is constant for you, your ruling is the same as that of a person with salasil (urinary incontinence or constant discharge).