Please dont panic. You have superficial bladder cancer which has a very good prognosis and rarely spreads to other parts. It may come back in the bladder later but even then it just needs to be removed through cystoscope and remains superficial. If at any of these resections it is seen to invade the underlying muscle, only then is it dangerous and needs more extensive surgery. The problems that you are feeling are probably due to the side effects of the bcg which causes urinary infections resulting in itching, burning, etc. Just get a urinary routine microscopy done and if it shows any infection, take a course of antibiotics in consultation with your doctor. Dont interrupt your bcg and take the recommended doses.You ll be fine.