Did you invest in Alteration? Mages aren't a problem for my Pyromancer since I have three ranks in Magic Resistance, and the Atronach perk. The Lord Stone helps as well. Also double casting Ebony/Iron Flesh with the stability perk, and 3 ranks in Mage Armor certainly makes it easier.
Wow, im level 43 and at 230 health. Thats where x3 60 hp enchants come in handy.
I'm lv 44, and 220 health. Even if my health goes down to dangerous levels(which it rarely does), I just cast fast healing, or if things get crazy then Histskin.
Man I love being an Argonian.