My doctor put me on 100 mg of Diflucan for 30 days, but I may continue another 30 days. He said that 60 days is the point at which there is danger of liver damage. Also, the half-life of the drug is 3 days, I believe, so it stays in your system a while. That means that even if you take a weekly maintenance dose, I don't think that 60 daily dose safe limit translates into 60 weeks; the drug will be in your system much longer than 60 days. I don't know exactly how long it is safe to take it weekly. I hope that makes sense.
Either way, I would be VERY wary of ordering a drug online without a prescription. You have no idea what you're getting. Maybe try calling a bunch of doctors and asking if they have experience with candida. Look for integrative or holistic doctors. Good luck.