Victor,
are you getting cisplatin daily? If so they are keeping you very busy; would you mind confirming this?
Do you have a PEG? Nutrition is going to be an issue especially later on. I did not have a therabite device. It would however be a good idea to start doing Jaw exercises. This is one of the things nobody on my team ever mentioned.

Don,
you should have a bit more time before it gets worse. Mouth sores will GENERALLY get worse and eating then drinking and finally even speaking will be "uncomfortable".

One thing I was using in my last weeks of rads was viscous lidocaine. you can eved dilute it a little if needed. This gives you short term relief for speaking/drinking etc. Even if you use the PEG you should continue to drink normally told otherwise. Lidocaine allowed me to cut down on the oxycodone/morphine which was good thing because they also cause problems (constipation etc). In the end I used about 1/3 of the oxycodone/morphine. The point is to use as much as you really need. You also might want to use a stool softener.

M