Yeast Infection HELP!?

I've had a yeast infection now for a little over a month now and at first my doc prescribed me diflucan and metrogel which didn't fully rid me of my infection.....it did help though since the only symptom i have now is thick discharge....so now my doc prescribed me 5 days of diflucan....I was wondering how long this will take to rid me of my infection completely?.....Oh and i've been reading about yeast infections online and some people say it never goes away which is scaring me a bit since i'm only 20 and don't want to be stuck with YI for the rest of my life.