Yeast infection

I'm very curious and would like to know how to get rid of a reoccurring yeast infection. I tried Monostat the doctor gave me fluconozle like 4 times and this yeast infection will not budge. I am so confuse as to why.i stop using tampons its still there I stop having sex its still there. What could be causing it? I eat very healthy so it's not that I don't wear tight clothes . Please help i have had it since the end of January it is unbearable.