From what I have read and what I experienced the peak of pain/symptoms was about 2-3 weeks AFTER radiation treatment was over. Then the slow climb back to somewhat normal taste, swallowing, eating foods you like, etc. And yes eating was a CHORE.. My guess it was about 2 months before I could get faint tastes ( which faded as I ate) and saliva production was getting better and not so thick. It was about a year before most all of my taste was back to 95% and Saliva pretty good. AND yes your taste buds are toasted. Thats what the radiation does unfortunately as it kills the cancer cells. I would think within 2-3 months of final radiation treatment you would be at 40% normal. It started with my tasting for a few bites and then fading through the meal. Try to be patience as It is a slow process. Of course everyone is different and depends on the radiation dose and areas treated.