Hey @Raich,
Scanxiety ugghhhh...if it's any consolation (and I know it's not at the moment) it does get easier down the road a bit. You have a double whamy with another biopsy. No wonder you're having a freak out. The fear of something else being wrong, did it spread etc etc etc. All totally understandable and bloody awful. I really dislike it when your body takes over and you can't control the tears and shaking in your boots.
Personally, I like the rolling drunk idea, that would give them something to talk about! Seriously though, just make sure you speak up and tell them how you're feeling. Some staff will care, others will just go about their job. Luck of the draw in that department lovely.
Personally, the grounding, stay in the moment thing doesn't work for me either. I tend to use music. I got through a barage of follow up scans and core biopsies for over 18 months trying to track another "suspicious thingy" by trying to remember the words to American Pie every time i would get in the MRI machine. No cheating, if you make a mistake you have to start the song again from the beginning. Just gives you something else to concentrate on. I also use going total zombie mode and shut down completely.
See if you can talk your gp into a nice packet of Diaz :)
All the best lovely. I feel for you sweet.