I've had it...totally feel your pain! It's the most excrutiating thing ever!
As MamaT said, washing - make sure you use a Canesten rinse for every wash for about a week after the symptoms disappear just to make sure it's totally gone and there's no chance of reinfection.
There are alternative antifungals you can use, Micreme-H, I think is one. I used Canesten because according to the pharmacist it's supposed to be gentler on your nipples but it needs to be wiped off before feeding.
My midwife ended up putting me on antibiotics, which seemed like the opposite of the right thing to do and I almost didn't take them, but I was willing to give anything a go...and within 12hrs I was feeling a bit better.
If I remember rightly it took almost 2 weeks for the symptoms to totally disappear, and possibly longer for DS (he had it in his mouth and bum)...there was also the mental side of it and the anxiety about feeding because of the pain.
Did you get IV antibiotics during labour just out of interest? I did and I'm positive that's what caused the thrush. I also got 2 jars of Inner Health Plus probiotics and took them twice daily until they were gone, just to make sure my internal flora was balanced again.