bacterial vaginosis symptoms

I've had this issue for over a year now, and every time I am getting it, I'm going to the doctor and they give me YUCKY flagyl! (eeew) It will go away once I am done with the prescriptions they give me, but four weeks later, it'll come right back. I have it as we talk, it came back 8 months about but I haven’t done anything about it. The smells so nasty, it’s to the point at which I will smell it through my garments. I'm an exceedingly clean person. I shower daily, wear ONLY but cotton undies, and change underwear’s Each night…. It still won't go.