Encountered a major bug in the dlc which has basicly ruined my save unless a fix is made/found.

Basicly what happened:-

Entered soul cairn as a vampire lord the first time, did the quest for serena's mother then promptly left soul cairn. cured my vampirism via rising at dawn so i could alter my appearance with the lady in the ragged flagon. I tried to go back to the soul cairn as a human to complete the arvak skull quest but couldnt enter (just stood in portal taking damage). I then became a vampire lord again via serena and entered the soul cairn again completed arvaks skull quest and then left the soul cairn.
However, since returning my characters health has been constantly draining while outside the soul cairn forcing me to heal every few seconds. I've checked my active effects list and there are no negative effects active other than the usual vampire lord ones, i also dont have any quests to retreive "soul escence".

any help ?

what ive tried:-

re-entering soul cairn both in vampire lord form and human form
eating soul husks (doesnt even suspend the effect for 10 seconds)
cure disaese potions
travelling to where my soul escence should be in the soul cairn if i had the mission (the chest is empty when i get there)

I dont have any other saves anywere near the point where im at now (lots of levelling has been done, many quests completed and such)

this has basicly made my game unplayable so a fix would be GREATLY appreciated!

Thanks