I did ok with treatment. I had IMRT, "every lymph node in your neck," I remember the RO saying, but more on the bad side of course, and my tongue. I think I did not have more radiation in my mouth because they had removed more of my tongue after I had the original small lesion taken. There was no additional cancer. Radiation was not too bad until the last couple of weeks, but I still managed to eat & keep the sores from getting to me. The 10 days after treatment lived up to its reputation of being the worst. Chemo was a bear for me, but probably would have not been had I not had another problem, which is too much to go into here. I had a GIST (gastrointestinal stromal tumor) which is a sarcoma that grows out from your GI track, in my case stomach. It gave me lots of digestive problems, resulting in constipation as well. I did not use pain meds, which is just me, and did not have a feeding tube. No one knew about the GIST which was large, had lived in my body for years, but is now gone and needs no further treatment. That story is in the general topics page if you want to know, but it is unrelated to oral cancer, so probably not.
Anyway, how your treatment will go depends upon a number of factors. I had a great will to get through it without using much in the way of pain meds (which was 0 until after treatment), and I wanted to keep my weight up. It became a goal and a challenge. I was religious about taking care of my mouth (baking soda rinses if/when I saw any sore) and tried to make some time in my life to read, watch TV, go to integrative medicine classes, which included exercise and meditation, etc.
You too can get through it!
Anne