Hi. I know what you're going through. I've been dealing with it since I was 13. I'm 39 now. I've been so far up and down and had to deal with so many situations I won't bother to talk about them, but I can tell you something I've recently discovered. Apple Cider Vinegar. It costs 2 dollars for a good sized bottle. Let me tell you what I've discovered.
Everyday for the last few days, after I shower and dry off (including between the cheeks), I pour a little less than a half a thimble full onto my left hand and rub the inside of my buttocks, taint, anus, and up to the top of the crack with the vinegar. The vinegar naturally kills stinky bacteria and you and may have had some kind of fungus or infection but let me tell you IT WORKS. Not to be gross but I putt a little on a finger and go in just a bit.
SO FAR THE PROBLEM SEEMS TO BE GONE!!!! TRY IT!!! AND SHARE WITH OTHERS HERE.
Also, I drink more water and have been eating Fiber One cereal. Adding fiber clumps everything together (it bloats you the first few days but it passes) and things move out of the body cleaner. Oh and I don't eat the High Fiber cereal every day by the way.
One more thing, I know this sounds obvious but try clenching your anus for long periods of time. I did this for 3 days (and I mean like 20 minutes or more its kind of hard) but one day it felt like things "changed" I wasn't relaxed down there and I think that may have contributed as well.
Good luck...God bless...you'll see improvement quick I promise.