-Before you start turning into a vampire but have contracted the disease, you can pray at alters (talos alter in whiterun works) to cure it before having serious effects.
But if you've already become a full vampire and got annoyed by it already,
Here's how to cure it:
-Make your way to Falkreth. Once there, speak to the owner of the inn and ask about any rumors going around.
-She will tell you that Falion in Morthal studies vampires.
-Speak to him and he will tell you that, in order to perform the ritual, a black soul gem (you can buy it straight off from him for about 300 Gold) must be filled.
-To fill it, cast a Soul Trap spell on a human target and proceed to kill them. Once done, speak to Falion.
- He will ask you to meet him at dawn, not far from his house. Once there, he will perform the ritual and you will be cured of vampirism.
Enjoy Questing Again.
To dumb to read? VIDEO of how to do it here: http://www.youtube.com/watch?v=ojSsWvKHK1E