Ok here's the problem, i have always had BIG problems with dehydration mainly off my own back from not drinking enough fluid, but recently i have been drinking alot of fluid as i recently had sex with my boyfriend and thought the cystitis i had day after was a reaction to the condom, but it went after a couple of drinks of cranberry juice

but then came back again the next day, and each day it goes and comes back, i have been having cystitis for as long as i can remember but never to this extent as normally when i've had it, it goes after i have rehydrated my body. I know for sure it isnt a water infection as i have also had that. And i am regularly checked for STD so i know i am clean. Any ideas? As it is rather expensive buying cranberry juice by the lorry load.