I talked to the pharmacist and they said its fine to take my xanax now since I was only prescribed one dose of the diflucan
You need to talk to your doctor or pharmacist. Did you get the Diflucan filled where your Xanax is filled? If so, they should have explained this to you and instructed you on how to proceed.
Basically, the Diflucan can drastically increase blood levels of the Xanax. It's great that you did your homework, definitely hold off on taking the Xanax until you speak with your doc!