Hello, I understand your concern. The symptom described by you is probably suggestive of a yeast infection.A fungus known as Candida albicans causes it. This is the most common type of vaginal infections. It usually presents with intense itching, red spots on the vagina and a thick curdy white discharge. The itching in your case may have reduced because you applied yogurt but the cause is unknown. I would suggest you to get culture and sensitivity of the discharge and you can start using anti fungal medication like Candid A cream which can applied to the vagina twice a day for a week. During this period, avoid sex and use a mild soap while taking shower and use loose clothing. If the condition doesn't improve, then you can consult your obg-gyn doctor. Hope this helps. Thank you.