Every city I go into I get attacked, and killed without fail. I was told that I need to cure vampireism and to go to Mothral to seek out Zalion (i think that is how you spell it), but when I go there to see him, he attacks me as well... I am unable to go into any town for any reason without getting hammered by 7 or 8 guys at a time....Any ideas on what I need to do?

Find a shrine? There's one on the road to the old city where you join the stormcloaks, look for the cluster of menhirs uphill from the ice flow with the walrus' on it.

Alternately, find some isolated farmhouse and feed.

You're on the final stage of vampirism if you can find a sleeping npc outside town and drink some blood it'll reset to stage one then you can talk to him and get the quest.

after you cure yourself of vampirism i strongly suggest you become a werewolf which will prevent you from contracting any other disease including vampirism and has no negative effects unless you actually use beast form and you can cure yourself of it any time. (once cured of it can never be werewolf again and lose disease immunity)

^This

You need to feed. To do so "Pickpocket" a sleeping NPC and it will give you the option.

That will reset you to stage 1 vampyrism (25% resist to frost, 25% vulnerablility to fire, weakend stats in daylight, and a few minor abilities)

The longer you go without feeding the more those bonuses and penalties are affected until you get 100% cold resistance, double damage from fire, VERY weak stats in daylight, and increased abilities. Oh yah... and NPC's attack you on site at stage 4 as well as you've noticed

If you notice the disease before you hit stage 1... you can cure it at any shrine. (You will notice -25HP listed under "Sanugine Vampyrism" under active effects" and every day it will say you feel hungry for blood or something") Once you hit stage 1 (not sure how long it takes... at least a couple days though) you can no longer be cured at a shrine and must undertake the quest to get clean or, if you haven't done it yet,

Three days from being infected.

there IS a downside to lycanthropy....

no rest bonus.

Sleep in your own bed and you get 10% XP bonus for 8 hours
Sleep in bed with your wife and it's 15%

VERY useful when power leveling your crafting skills. Combine with "The Lovers Stone" bonus for +30% XP on all your crafting.

Cure disease potions aren't that rare, can be created, and worst case scenario you can always hit a shrine to clear diseases between quests.

Lycanthropy is only worthwhile if you actually use the ability a fair bit... BUT... your follower might attack you O.o restricting your available followers to the Companions.

It can be a fun playstyle and character ability... but it DOES have it's downsides.

Personally I cured it when given the chance.... though I've rolled up an alt Orcish warrior that will probably keep it if I ever get him that far I've got 3 mains I'm working on already.... my dedicated werewolf and Vampire characters are both sitting below level 10 right now not getting any playtime

If you have the Lovers Stone activated, you can't also have the rested bonus.

unless your actively trying to power level up the resting bonus is pretty much useless as doing two quests will almost nullify the time restraint. As for me i rarely rest so the bonuses for lycanthropy greatly outweighs the minor inconvenience of no rest bonus. but you are right there are some cases in which using beast form is a great help, ( i ran into a frost troll,a giant, a dragon and 3 bandits all at the same time and beast mode along with my horse was a great help