Christina,
I’m sorry to hear about your ordeal, it sounds like you’ve been through hell.
I would strongly advise seeing a urologist for help. You need to find out why a catheter is needed in the first place. Is it because of a stricture from the cancer treatment, or is it neurogenic, where the nerves no longer function properly? A decent urologist will be able to find out.
As far as how long your bladder will work after having a catheter, I can’t give you an absolute certain answer, but I can assure you that it’s a long time. Many people with strictures deal with catheters for many months or even years before their surgery, and their bladder function returns to normal. I had a catheter for over six months, and my bladder was normal after only a few weeks of being used again.
Did they ever tell you the reason for your catheter?
Clayton