Hard time tanking stronger monsters

[Spiker]

Anybody else having a hard time tanking vamps, or even anything with really good items? I am currently 91 AC and here are my resistances:

physical +99
magic -26
fire +30
electricity +0
cold +20
confusion +0
acid +0
drain +100
weapon magic +0
ghost hit +0
poison +0
slow +0
paralyze +0
turn undead +0
fear -100
cancellation +0
deplete +100
death +100
chaos +0
counterspell +0
god power +0
holy word +0
blind +0
life stealing +0

I used to be able to tank vamps, ever since I switched to Ogma I wasn't able to, so I switched BACK to Brigid, and now I can't even tank Ice Fiends...Wtf is going on?

Nico, I know you're going to tell me it could be anything, but I am looking for information from other players that have experienced this as well.