The cause of all your problems seems to be digestive issues. The sweet BM smell is usually associated with intolerance. Intolerance to what? Who knows, you're gonna have to experiment a bit...
The fecal odor is connected to the pressure you feel in your rectum. It could be degree of prolapse that is causing your intestines to push against your internal sphincter, thereby opening a gap where gas can escape, or your body is slowly pushing out the contents of your stomach... with similar results. This is a symptom of constipation sometimes.
If you don't have constipation (sounds like you might primarily experience diarrhea?) then you could have leakage that you haven't noticed because of the sweat present in the same area.
The fact that it got better with Antibiotics for a while suggests intestinal dysbiosis - but whether that's a cause or result of another digestive issue is hard to say (this would also explain skin and past BV symptoms). Either way you're going to have to balance your internal flora.
If you haven't already, completely cutting out dairy, red meat, and sugary fruits will make a big difference. (my guess is the sickly sweet smell is undigested lactose or fructose)
Start taking probiotics every day.
Cut out breads, you don't need them. Vegetables are the healthiest sources of carbs. Breads are delicious, but unfortunately the bad bacteria in our gut seem to think so too :/ best to stay away from it.
If you cook with olive, vegetable, sesame oil etc. use a very small amount. I mean just enough to prevent the food from sticking but not enough to really flavor or grease up the food.
Used to think that I was very healthy cooking with olive oil. Damn was I wrong, cutting out oils made a huge difference in my Body Odor . Also, if you must use oils, coconut oil is the way to go.