Good Luck! Getting the instrument rating is a major accomplishment.
I'm sure you're as sharp as can be right before your ride, so just relax and keep staying a couple of steps ahead of what's happening -- tuning your radios for the next thing (or the thing after that), briefing approaches out loud well ahead of time, etc.
A cold beer never tasted better than after my instrument ride! That checkride was also the last time I flew a nosewheel airplane.
Good luck!