Just read your post - hope it all goes well and you sound as though you're up for the difficult times ahead.
I had cancer on the base of my tongue.Had my surgery in July 2011 and then 6 weeks of radiation (30 sessions) and chemotherapy (6 sessions).I've since had another 18 weeks of chemo - but that's another story.
We are all told that our own reaction to these treatments is all different.Personally, I was ok to drive and generally 'function' for the first two weeks or so of my radiotherapy - though I was off sick from work due to all the medication I was taking.
Gradually, the side-effects of the radiotherapy began to kick-in and I felt that these were worse than the chemo side-effects for me.My taste sensation went fairly quickly,as did my appetite and I relied on my PEG feeding tube.I felt as though my throat was being slowly burned by the radiotherapy and swallowing anything (even saliva/water) became a bit of an ordeal - though I did manage to keep it up.
I produced a lot of mucus in my mouth and throat which I constantly spat out and this continued at it's worst throughout the night - I'd say for about 2 weeks,a month after treatment had finished, I was sleeping in 30 minute slots.
It took me three and half months before I began to eat normally again after slowly graduating from liquid food and mush as my throat recovered.
It is tough, very tough, but doable.
Good luck.