Welcome, but sorry that you had to join us!!
You need to find out a bit more about your tumor diagnosis. I seriously doubt that it was a "4" because if it was that is about as bad as it could get and you would be in the hospital having your bladder removed!! BCG is given when the tumor is still localized in the bladder lining and is considered "high grade." You should ask for, and receive, a copy of the pathology report from your urologist and save it for your records. That way there is no question about what the initial diagnosis was.
It appears that you most likely have a very treatable type of bladder cancer. BCG is a great treatment in these cases. Its purpose is to "kick up" the immune system which then fights to reject the cancer cells in the bladder lining. Often as the treatment progresses so do the side effects.....and this may indicate that the BCG is working! Most of us who have had BCG treatments also have maintenance doses following the initial 6 weeks induction treatments as these have been shown to increase the effectiveness significantly
Once you have your path report you should be better able to understand exactly what you might be facing. And we might be able to answer any questions you may have,.
Best of luck to you
Sara Anne