I have suffered with this for years, maybe initially from being in the swinginging scene for years but I put it down to hard/rough sex, rimming, fingering, basically many things expected/offered during escorting.
I was finally diagnosed with having a sensitive bladder and prescribed oxybutynin tabs 2/3 times a day. The crap side effects are that they make you insanely thirsty.
As Amy says, taking a break is great, when i'm not working it's no prob at all. Just had 2 weeks off and felt fine, didn't need the meds but one day back and two bookings where both went in with fingers (despite the fact that I removed it from my enjoys list ages ago!) and being told to be gentle and I'm getting the irritable rumbling warning signs.
I used to get D Mannose from the suppliers website and found it very helpful but it eventually became very expensive, looks like now prices are a bit more competetitive so I'd definitely recommend but also don't allow rough/PSE sex, fingering and rimming or excessive use of toys.