I had bacterial vaginosis and yeast infections for as long as I remember. I tried everything you mentioned in your post to no avail. I even tried boric acid which is a great temporary relief. A few months ago I decided to stop eating eggs and processed foods in the morning. I would eat one/two eggs per day (runny) and I would accompany that with turkey bacon and sometimes bread...I did this breakfast everyday for a long time! For some reason I decided to stop eating the eggs and the bacon and replaced it with chobani yogurts in the morning, That is the only thing I changed in my diet. I am not a vegetarian, I like to eat everything. I have been clear for about two months now. No smell, no discharge, pretty normal, when before it'd be normal for a week and repeat itself.
Everybody is different, this is my experience and my assumption, the eggs were the culprit in my story, at least I think. I am not even sure if that is the reason why they stopped. Whatever the reason, I am happy now and glad that this nightmare is over. Good luck to all the ladies still going through this. I definitely feel your pain!