Gentian violet. Not sure of how to use it, but I know that's the magic cure. Its messy, staining stuff, so you definitely want to get good instruction in its use.
Probiotics for you. Get good ones from a good source, which have more than a few organisms listed. Natural food stores have them.
Call your midwives. They aren't in office until then but they are always available for emergencies and births. They may be able to help you over the phone. They may make a special trip for you if the can't. Or they will tell you who you should see to correct the problem.
Best of luck to you, I haven't had thrush but I have had mastitis. Not the same at all, but a nasty problem, nonetheless. Thrush can be very hard to get rid of, make sure you boil/bleach everything you own in order to get rid of it, you may need to do that a few times to break the chain. Limit your sugar intakes as well, including breads, pastas, fruit, etc since yeast feed on it. Give the "girls" lots of exposure if possible. I believe sunlight is good for helping you too, so if you can, go outside topless. With caution of course, you wouldn't want to entertain the neighbors.
Good luck! Keep nursing and don't just use the stuff we use on our vaginas for yeast.