Another chronic yeast infectioner over here (is that even the right term? LOL). I suffered for about 15 years on/off with the usual symptoms of itchiness, redness, discharge, HELL ON EARTH. I found Monistate 3-Day ovules to be the most helpful, and that includes trying prescription oral dose medication, which NEVER worked. Out of desperation while I was pregnant (I was SO scared to get a yeast infection) I took my doctors advice, which I was hesitant to do, and stopped wearing underwear. It took me a long time to get accustomed to this, but I was willing to try anything at that point. I also started shaving the private area entirely. It's been 4 years and NO yeast infection. Sorry if this was TMI.
Don't forget to wipe front to back after #2. My aunt was wiping back to front and would get yeast infections all the time and it never occurred to her that the bacteria was entering her vagina.
Another suggestion, be sure to urinate before and after sexual intercourse, just as others have mentioned.
I'm sorry you have to go through this. Very helpful suggestions here.
Good luck & take care,
Natasha