I think this has been covered well but just to add some points:
1: Condoms... are all safer sex not 100% Safe sex.
2: If you do catch something, always go to your GP or clinic quickly and always finish your course of medicine. The most common reason these bugs become resistant to the medicine is people stop taking then when the symptoms stop, just because the symptoms have gone doesn't mean the bug is gone.
3: If you do get something, don't panic, We still have medicines of last resort for most things. You may have to be administered into hospital for treatment but your dick isn't going to need to be amputated. But also don't underestimate the seriousness of this.
4: Know your risk, a £60/hour SP who offers BB/CIP fully included is going to be a far higher risk for even OWO than a £300/hour SP who doesn't do BB. That said their is no reason to expect that the more expensive SP is clean, maybe she has regular BB with her 'BF' who is BB'ing the £60/hour SP behind her back...