Jo ~
I think your feelings are quite rational. You're worried about a re-growth and fear what's next but until you have a definitive answer, I would do what I could to stow the fears until you've had the MRI scan. Although the tumor may be growing and your symptoms are real, you might also be hyper-sensitive to any changes and the re-growth, if it's occurring, may not be as dire as you think. Of course, I hope that is the case but because you won't find out for certain until early February (and the MRI scan) I concur with the previous posts that are encouraging you to take that vacation to Mexico and try to enjoy yourself for awhile.
Your determination not to indulge in self-pity as you go through this is wise and admirable, although often easier said than done. Venting is always helpful and if you can't vent here, then where?
Know that lots of folks are following your situation (via the forums) and rooting for you, Jo. I think you'll get through this and conquer your AN once and for all, very soon.
Jim