As someone who is now three months post-radiation (and writing this note from work, where I'm back to almost full time!), I can say honestly hang in there, there is a light at the end of this dreadful tunnel...
I had to laugh out loud at your post, Erik, because I think I said the exact same things during my roughest days, even beat up a helpless pillow or two, much to my wife's chagrin. I especially couldn;t stand the thick saliva/gook that didn;t seem to go away...
I set a lot of goals for myself and kept an eye on folks on these boards who were a few weeks ahead of me. I remember one woman said she ate tempura shrimp and other wonderful foods just 13 days after her last treatment -- that drove me to push through and try and beat her (which I didn't do but was close)... I had Red Lobster about a month after my last treatment
I know for me, I turned a big corner the week after my treatments ended when my doctor prescribed a steroid treatment for my mouth. Not sure of the name, but it brought a lot of the swelling down fast and I went from not being able to sleep more than a few hours (without waking up gagging) to getting through the whole night. Gauze and Puffs tissues also work well as a temporary measure for wiping out the mouth...