Oh your poor thing! I have had a few of these, one where I had to be hospitalised because I left it too long and chunks of something were blocking my duct to get the urine out... SOOOOOO PAINFUL!!

Definantly go get some cranberry juice, I found that drinking 2 cups of this would almost instantly ease the pain. If you leave it too long it will get worse like mine did, I had to walk to the shops to get pills and 3 times I had to pee in peoples front yards.
It is the worst thing I have EVER experienced. Good Luck, hope you get better soon!