BV is a broad category that includes yeast overgrowths, the most common problem for modern vaginas due to the amount of sugar consumed.
Yes it is possible to have an allergic response to a man's semen.
Yes, you can get OTC remedies for this.
There is a product called D-Manose which is a white powder taken with water.
I too ended up using d-mannose years ago and it works
These mischievous bacteria thrive when you have an abnormally alkaline environment in the vagina.