Boric Acid??

My doctor told me to start doing boric acid suppositories due to chronic BV & YI for the past 2 years. Is there a certain kind to get?? And how long do I do it for and when should I do it? after period or before and do i stop when i have my period?

She also told me i can take a probiotic with it. But i have high anxiety with taking pills would yogurt be enough?? and if so what kind??

Thank you!!