What Could Smelly, Brownish Discharge With Painful Vagina Indicate?

I have had pain bending and sitting down and noticed that my pants got wet and I didnt know how so I felt it and smelt my finger and it was horrible. I go to the bathroom and wipe my ass thinking I sharted but it was like a whiteish brownish yellowish ooze that smells bad and it started oozing as I tried to get a better look. It is still painful and I have tp on it and a towel in case I leak to much. So im wondering what this is and how long it will last and what I should do. Also what can cause these.