I was originally diagnosed with overactive bladder syndrome, and prescribed all sorts of different medication (none of which worked) and eventually had Botox injections for it. They worked really well and, even though it has been over a year, it still is not as bad as it was. (Botox wears off, but hopefully the improvement will last - if not, I might have it done again.)
Unfortunately, it didn't stop the recurring UTIs and nagging pain, so now I'm diagnosed with painful bladder syndrome. Again, nothing seemed to work, till the consultant suggested long-term, low-dosage antibiotics, which are helping a lot (touch wood!)
So, my advice is don't give up. Get a referral to gyno-urology, and keep trying different things until you finally gets something that works. Don't suffer in silence for years, like I did, before seeking help.