Oh god, it's like reading my own test experiences on here....I have taken mine 5 times and nerves have gotten the best of me every time. Just like Ringwood and Floella's comments, I am a good driver but I go to pieces when the exminer gets in the car!
Havinmysay, I would suggest relaxing tonight, try and do something to keep your mind off it (coz if your anything like me, you will work yourself up and not sleep well tonight). Friends have told me rescue remedy or kalms worked for them, but I haven't tried them so I wouldn't know. There really aint anything I can say to you, other than, I know how you feel but if you just think to yourself, 'I will pass one day', it kinda takes the pressure off yourself!
GOOD LUCK, my fingers are crossed for ya! PS, What time is your test coz the vodka thing might work if you have enough time for the alcohol to wear off!