So sorry to hear that it has returned. Unfortunately, bladder cancer has a nasty habit of doing that.
I would really recommend that you get a second opinion at a center that treats a LOT of bladder cancer cases. Yours is not a simple situation because of your other health problems. Also, urologists do not always agree on how to treat a first recurrence such as yours. If you let us know where you are located geographically, some of us may have suggestions as to where you might get a second opinion.
Chemo is used when the cancer has spread beyond the original site. If your doctor is SURE that yours hasn't, chemo would probably cause more problems and there would be no point in it.
When you say that you had three "installs" of BCG, do you mean just three treatments or three SERIES of treatments? The usual BCG protocol, especially for CIS, is 6 weeks, once a week, then in about three months maintenance treatments start...once a week for three weeks every three months until two years have passed.
Please consider getting a second opinion ASAP!
Sara Anne