Uber Sorc's Math - Oneshoted at NM Dungeon 91

Hi Blizzard/Microsoft dev team!

My Non Season - Sorc character is @ level 100, equipped with Shako, two uber-unique items (the best two-handed weapon). My Ball Sorc gets one-shotted in the level 91 Nightmare dungeon. It wouldn’t be a problem if I were only at level 90 and didn’t have good gear. But shouldn’t it be natural that if someone has 2-3 uber uniques, then the gameplay should be UBER too? Instead, it feels as if I’m wearing low quality items. They look just nice.

My all resistance is maxed out! 70-70-70-70. 15000 Life. Armor is as high as it can possibly be. I understand,the nerfing of BL damage, that’s ‘tolerable’, (btw not fun 2 play) but what is with the armor? It is unplayable. I play with my dog, or something else.:))

I love math, I studied to be a mathematician, and if there’s way, I’d be happy to make Diablo IV or V math fun. PM me!
Kind regards