ok
i know what its like!
TREATMENT
1) Drink lots of water. like, as much as you can. you need to flush out the infection.
2) 'Oasis' sachets or similar (if you have them - unlikely i know). Taste yuk but really help
3) If it continues, go to the doctor
PREVENTION
1) Make sure you pee and shower after sex, and keep clean generally of course, but I'm sure you do.
2) Drink cranberry juice: alters the pH of your pee and stops bacteria multiplying.
3) Stock up on Oasis sachets, so you can treat it if it comes back. Once you get it, you're more prone to getting it again.
Hope you feel better!