Hi J.,
I used to get yeast infections three times a month or more. I used everything under the sun: yogurt, Monostat (the 7, 3 and 1 day kinds) and prescriptions. They'd take care of the infection, but it would come back in a week or so.
I talked to my fiance and we made sure he didn't have one as well (men can get them, though rare). It turned out that it was a reaction to the birth control I was using. The estrogen dose was too high, and as soon as I switched to a different pill, they vanished, and I haven't had one since (it's been about ... six years?) One gynecologist I saw said birth control would never affect me like that, but as soon as I changed doses, I was fine.
Another thing, when I used the over-the-counter Monostat, I used both the name brand and generic. They both have the same ingredients and work exactly the same (one is just more reasonably priced). Also, I noticed no difference between the effectiveness of the 1-day and 7-day methods, so whichever you prefer is fine. (as soon as I used the 1-day Monostat, I never used anything else).
The only other thing I could suggest is have your gynecologist run tests for other underlying causes. Maybe the yeast infection isn't the problem, maybe it's a symptom of something else (like a reaction to something in your diet or other meds you take).
I hope this helps. I remember how painful and annoying chronic yeast infections are.