Bill

At 70 you are old enough to know better than to wish and hope that some magic diet can cure or even slow down cancer but young enough to be given false hope by the internet and talk show hosts and celebrity know nothings.
Easy enough to understand why you might think that "watchful waiting" is an option since it turns out that simply doing nothing works the best for the majority of prostate cancer cases in men of a certain age like ourselves.
But oral cancer is a totally different beast than sleepy and lazy prostate cancer.
In order to even give you a guess about "how long you have" we would need to know what stage of cancer and how big the tumor was. Even then it's a guess. Only a biopsy and pathology report can prove that you even have cancer at all. Your use of the phonetic spelling of metastasized implies that you had cancer of the base of the tongue and that cancer spread from the lymph node. I had the worse stage ( stage IV and a big tumor (T3) and my doctor estimated I would live about one year without TX. The pain in my ear from the tumor was excruciating and unrelenting but otherwise I had no symptoms.
You have had enough lecturing, so let me just say you should start looking for a hospice now that has liberal morphine policies because without TX, base of tongue cancer is a hideously painful way to die. Again,if you have not had a biopsy, you do not even know if you truly have cancer.
Charm