I love Oblivion, I pretty much beat the entire game.
I'll help you out Mario. Go and talk to Raminus Polus at the Arcane University about a Vampirism Cure. If that doesn't help, then go and talk to Vincente of the Dark Brotherhood and he can cure you of Vampirism.
To talk to Vincente, you will of course have to become a part of the Dark Brotherhood beforehand. If you haven't joined them yet, then all you have to do is simple.
Kill an innocent person and escape. Then sleep in a bed, and a surprise will be waiting for you when you wake up.