How Can Waist Pain And Vaginal Area Darkness Be Treated?

Hello, I'm 27 years old girl. I'm a Computer Programmer. My question is that i'm suffering from waist pain since last 1 month. I consult a local doctor, She gives me medicine. I get rid from pain only while i'm taking medicine, but when i stop to take medicine pain becomes active again. Also i'm getting married within 3-4 month, so i want to get rid from this pain. One personal question is my vaginal area becomes very dark compares to my other body part, so what can i do to make this area better and make same as other body part. Please note that i'm using hair removing cream to remove hair from their.