What Causes Burning Feeling And Thick Vaginal Discharge After Having Sex?

Hey, I want to know why after I have sex, I am in pain. Mostly a burning feeling. I am having a discharge that is thick and white and somtimes reddish. I thought maybe it was a yeast infection. I took the 3 day Monisat, but it came right back. About a month ago, I was diagnose with BV. I had the cream, but it seems like the infection is back. im constantly having a foul smell and discharge.