Kvatch questline at level 5

Hello,
I'm currently working through the Kvatch questline and finding it quite difficult. My character is a mage who also uses a longsword, and I'm at level 5. The problem is that I do almost no damage with melee attacks—only my spells seem to be effective. However, I have to use nearly all of my magicka just to take down a single enemy.

Is it normal for this questline to be this challenging at my level? Would it be better to level up, improve my gear, or adjust my character build? Does my build just suck in general (I have pretty much only focussed on level up luck, intelligence and willpower).