Problems after the TVT Sling procedure for incontinence

I have had my tvt sling in for 6 weeks now, and although I no longer wet myself when I cough or sneeze, my incontinence has got worse. For instance, I was on the motorway and needed the loo, so I stopped at a service stattion, and went to the ladies and performed, walked back to the car, and wet myself without any warning before I had chance to even unlock the door. This has happened countless times now, and it just comes in a flood without any real warning. I also have 2 little lumps either side of the pelvic bone, and they are verty sore, I assume they are the 2 ends of the tape. but I am now really regretting having had the procedure, as I am so much worse. I live in Oxford, and had the op at the John Radcliffe hospital. I'd love to hear from other women who have had it done there, as they say that over 95% of their ops are successful.