Why Do I Have Severe Vaginal Itching, Swelling, Chaffing And Vaginal Discharge When I Am Postmenopausal?

Hello I am a 47 yr old postmenopausal female I had a partial hysterectomy in 2010 for several months now I have had severe vaginal itch severe vaginal swelling vaginal chaffing and vaginal discharge. I ve tried over the counter yeast infection medicine but it makes my symptoms worse