An ultrasound via vaginal route or a uteroscope inserted via vaginal route to look at the condition of the cervix, uterus etc, a PAP smear, a vaginal
swab test, a culture of the vaginal discharge
, a complete STD panel are probably what are required. It could also be an allergic reaction to soaps, cosmetics, douches, razor etc that you use. Hence eliminate them one by one and see if it helps. It is difficult to comment beyond this at this stage. Do consult your doctor/ gynecologist.