My old instructor had me use her pink Hello Kitty calculator on all my checkrides from private to CFI.
There's no better way to relax and laugh a little on a stressful checkride than to look down and see that you're punching in complex weight and balance calculations on big pink buttons with sparkles.

Good luck with the rest of your sim rides. Since I will be doing the same thing soon, I can only imagine that the first few times in the sim I will be consistently 5 miles behind the plane and I will loose even more hair from the top of my head.

If you are meant to be a pilot, at some point everything will all click into place and you will wonder why you worried so much. I think its really a rite of passage in the airline world. Nobody said it was easy.