Frost Damage

So I've been playing a Nord Vampire for a while now (level 48) and I think something is wrong with frost damage in particular.

For some reason even tho I should technically be taking less frost damage than fire or shock I pretty much get one shot by any Adept or Expert ice spell and idk why that is happening since as a Vamprire Nord I should have around 75% frost res and I have no res to the other elements yet they dont one shot me and its making encounters pretty much impossible as a warrior unless I cower in the corner spamming ranged attacks.

I have Mannaz, Freyr, Odin, Vokrii (with the patch that gives it to npcs without player disarms), Growl, Sacrilege and Summermyst (Beta).