Hi there, the fact that you have hep c, Rheumatoid Arthritis and lymphoma spinal cancer does some what complicate your case, and to me says that you will need to be very careful about self-medicating. It all depends on what meds you are on, but not being able to pee is pretty serious in my books and there could be many different causes for this. I highly recommend you talk to your doc and get this resolved ASAP, you will create many other serious problems if your urinary system AND your liver (hep c) are not functioning well.