All right, straight to the point! There's too many questions about this blasted curse.

Go to the Imperial City, and find the Arcane University. Inside, look for Raminus Polas; talk to him and he will send you to a witch named Melisande. She will offer to help cure you, if you can acquire five empty grand soul gems and give them to her. You can buy a soul gem for 350 gold from each of the Mage's Guild.

After you give her the soul gems, she'll ask for you to find the ingredients for her potion. You'll need to find 6 garlic cloves, 5 nightshade leaves, 2 bloodgrass, ashes from a vampire, and Argonian blood. Take the ingredients back to her, and shortly after, you'll no longer be cursed.

Grand Soul Gems

Most branches of the Mage's Guild have a person who you can buy the gems from. In Anvil, you can talk to Felen Relas. In Chorral, Angalmo. Bruma, Selena Orania. Leyawiin, Alves Uvenim. Bravil, Ardaline. (Place, Person)

Or, if you're feeling adventurous, you can go out and find them yourself (this would be the manly way, men!). There's one soul gem in Melisande's basement. Two more in a display case at the Chorral Mages Guild. And there are two more at the Arcane University - one in the Mages quarters, and another in the Archmages Tower lobby. There's also one grand soul gem each in Squandered Mine, Crayfish Cave, and Ayleid Ruins.

The ingredients

Bloodgrass - you'll have to find these out in the fields. There /is/ ready-made bloodgrass in Cyrodiil, but you have to be far along in guilds.

Garlic - look in Summitmists Manor.

Argonian blood - use the enchanted dagger that you got for this specific purpose. You can get the blood from any Argonian, just hit them once with the dagger.

Nightshade - go to the Market District in Imperial City and enter the Main Ingredient shop. On a table you will find the nightshade.

Vampire ashes - Hindaril is in Redwater Slough, on the on the east side of Panther River. (it helps if you have a spell of some sort that will imobilize him; if you keep him from reaching his coffin, he won't have a weapon to fight you with, which would obviously make the job easier)