What Causes Vaginal Discharge With Foul Smell From Vagina?

Hi i am an ftm and have been on t for 4 years I am 45 and 5 5 weigh 155 pds. I have noticed that on the inside of my vagina it smells really bad. I noticed while having intercourse. The outside of my vagina does not smell at all and the discharge does not smell at all. I have not had a period in 4 years and I was wondering if this is an indication that I need a hysto Thanks Keagan