I have news for you... tomorrow will be the same or worse... hate to burst the bubble. Usually radiation (its cumulative) continues to worsen for around two weeks after it finishes. It sucks but those are the two worst weeks of treatment.

Re the gunk... I have said this so many times I am certain the company owes me money - WATERPIK. If you have one great - use it - if you don't try to get one. The deluxe model. IT has this handy dandy little tongue scraper. If you fill the chamber with water, and maybe add a bit of mild non alcoholic mouth wash, this will clean up the gunk, and freshen. Use it with luke warm water and the tongue scraper end (the pointy ends hurt like hell - because they focus the spray) the tongue scraper looks like a spoon and kinda just shoots water all the way around. It is good because it can clear out any food particles. It's also great once you've healed as you can use it like dental floss - hopefully this will help stave off any dental issues (assuming you have teeth..)
anyway good luck finishing. hugs