I was told as well if it is thrush to avoid sugary foods, because it makes it worse i'm always getting it. When i was pregnant i had to get up in the night and use a damp towel to ease it why i slept.
It sounds like thrush it burns like mad, if you see your doctor they will give you some cream for the itching an burning, and a tablet to get rid of it. If you have a partner then they need to use the cream to. Because he will just keep passing it back to you that's why you could be getting it every month. Thrush can be caused through wearing tight pants or even soap in the bath. But it can be passed and if your partner is not treated you will just keep getting it.
I have had this, but not on a regular basis. I never connected it to intercourse, but it may have been. Have you tried douching? I have used a mild vinegar douche and that was soothing. Don't bother buying the little bottles of premixed douches, they do nothing. Buy a bag and mix your own, about 2 tablespoons to 4 quarts of warm water and let the flow of water run as slowly as possible. This is probably an old fashioned treatment, but sometimes those are the best. Good luck and I hope this helps.