So sorry to hear about your diagnosis. Everyone here is either a patient or a caregiver, so you have lots of friends.
First, you are in an excellent place for diagnosis and treatment. They are "right on" in recommending a second TURB. Too often this is not done. The first time the uro takes samples where he thinks the tumors are. The second time, with results from the first go-round in hand, he has a much better idea of where the problem sites might be. My diagnosis after the second TURB was quite a bit different.
If you feel that you really need a second opinion, Johns-Hopkins will do a review of the pathology (slides and diagnosis) by mail. Besides Mayo, other top bladder cancer centers include Memorial Sloan Ksttering in NYC, USC in Los Angeles, and MD Anderson in Houston.
Partial cystectomy is not often used in bladder cancer cases, because the entire bladder is at risk of recurring tumors. It is occasionally used in a rare type of bladder cancer, adenocarcinoma. I am not a physician, but I strongly doubt that it would ever be considered with the presence of CIS....which is sort of like a rash on the bladder lining.
I do know that, should it come to cystectomy, it is not the end of the world. We have members here who drive race cars, go scuba diving, and yes, have satisfying sex lives with no bladder.
Don't blame you for freaking out. Been there, done that. I remember coming home from my diagnosis appointment and thinking (calmly, I then thought) "well, now I know what I will die of." My internist suggested that I "might be depressed." That really made me angry...I HAD EVERY RIGHT TO BE DEPRESSED. Well, 7 years later, no recurrences (yet), and doing great.
You will get through this, one way or another.
Sara Anne