bacterial vaginosis

So this is not a topic fun to talk about lol.  I was diagnosed with this about 3 weeks ago.  Dr gave me metrogel and about a week after treatment the culture came back positive for it so dr wanted me to take flagyl- but there are mixed views on taking it while breastfeeding so I requested the gel again( my dr wasn't thrilled).  I have never had this before and have read horror stories of women having a reoccurring one for ever!   I am curious if it has something to do w vaginal delivery, tearing  and stitches?  Or it just randomly occurred at this point in my life?   Any of you ever dealt with this before?  I do take a probiotic( plexus probio 5).