How Can Body Imbalance Be Treated?

I am an 87 yr old white male with stage 4 prostate cancer who has received radiation treatments successfully. My biggest and current problem which no one seems to know any answer to, is that I have chronic instability, to the point I have fallen 5 times (without fractures fortunately) and am now in Physical Therapy to try to pin point the problem or get medication. The therapists seem to feel its not my brain, or feet, but most probably inner ear ( I am much worse with eyes closed than open). I have my first apt. with a neurologist on 2/27 but she was educated in Haiti in 1997 and I am very skeptical !!