What To Do For Vaginal Discharge When Having Infection?

hi there, i had a vaginal infections and according to my research here in internet it is like the so-called yeast infection. it started last june 15, 2011...and i went to the doctor, she gave me flagystatin suppository. at first, it decreases the itchy and burning feeling.but it still keep reccuring..she also gave me fluconazole which is bit expensive..so i have tried once only..and then i continue using any metronidazole tablet. i am just wondering and worried, why my vaginal infection keeps on coming tho im taking meds. i have touched the side og my vvagina, which i guess is vulva, i can feel a bit of rashes there.and lastly, i really wonder, when i smell the white discharge, it smells like medicine..is that possible that whatever we eat and drink will be the same smell of my discharge? i am really hoping for your answwer because im really worried.. thank you so much..