Suggest Treatment For Severe Vaginal Itching

I am 44 yrs. old, and my menses has stopped since Feb 2016. I have been experiencing vaginal itching very often. The doctor prescribes me some cyclobacterium cream for application. After applying, the itchiness vanishes but after sometime it persist. Later in the month of Jan 2017 white discharge which is creamy starts to come out of the vaginal area and followed by persistent itching. It was only on Feb 02, 2017 that some discharge like blackish colour comes out from the vaginal area, but now a heavy flow. I consulted with the Gynae who checked my vagina (inside) and told me that there is no need to get worried and prescribed me cycloset syrup an ayurvedic medicine. Does it mean that I have got diabetes. Actually, I have done sugar test before which shows negative result. Would you please help me understand the problem.