Sorry for the late reply. Have you gotten this biopsied yet? I would absolutely push for a biopsy. I had an oral surgeon and ENT both examine my sore and tell me it seemed fine -- and they were very surprised when my biopsy came back as cancerous (fortunately the oral surgeon opted to biopsy it, even though he thought it was probably nothing. Thank God for him). Especially since yours has been there for such a long time, you really need to get this biopsied, in my opinion. My sore was caused by friction. It got worse over the course of a year. It didn't really bleed; it was more of a canker sore on my tongue that turned into a bump with a white ulcer on it. Apparently mine didn't look like classic tongue cancer, according to the oral surgeon. But he opted for the biopsy just because it had been there for such a long time. So, if I were in your shoes, I'd remind the doctor that your sore has been there for a long time, which in and of itself is not normal (as far as I understand it), and ask for a biopsy.

Keep us posted!