When you are a werewolf you are resistant to all diseases, but with the Dawnguard DLC you have the option to become a vampire, however you won't be a werewolf anymore.
Use you vampiric drain spell against him. It will heal you and harm him simultaneously. If you are low on magicka, use the Equilibrium spell found in Labyrinthian Chasm and...
It may be that the battery on your controller has failed. Many repair shops can replace the battery for you. Or, if you are familiar with electronic repair, you can...
No, they will usually give you a chance to cure yourself from the vampirism curse and give you a couple of days to do so before they start attacking you.
You can but don't wait too long or you'll lose your number. Maybe three days maximum, then you may have to start a new account and get a different number...
Nope. Sims appear to have infinite plasma/blood which could be so that vampires have an easy way to replenish the thirst need or so that Sims couldn't accidentally be killed.
Hold down Ctrl-Shift-C and type "TestingCheatsEnabled true". Shift-click your mailbox and press "Make me some friends". Eventually there will be a vampire.