stuck and need help! Shivering Isles SPOILER!

[Damn Snakes!]

SPOILER - ALERT -

I am exploring around after beating the Shivering Isles main quest - and I have traveled through a dungeon south of Bliss (Xed-something) and ended up in 'secret garden of dementia' part of the big castle which belonged to the now demised duchess of Dementia - I chose to become the Duke of Mania and so I never received any keys to this area... and now, even though I am their "Lord", the Dark Seducers are determined to kill me... but worst of all... I cannot open any doors surrounding this garden! they all say "cannot be picked - must have key" and the way I got into the garden *statue of Sheogorath* won't let me back down! any 'key' codes out there? I am running out of health potions and invisibility potions!