Just a suggestion (because I'm playing a warrior, albeit one who's invested a lot more skill points on magic than she has on warrior skills), but if you're lucky, or you're prepared to reload like crazy, then you might be able to find a weapon you can use with the mana drain ability. I did, and I love it. Sure, it does somewhat less damage than the other sword I carry around, but it gives me the ability to keep on casting Restoration on myself if I need it because pretty much every time I hit someone, my mana goes up. I've hardly had to recharge my mana since I got this sword.
Granted, I spend a lot more time up close and personal than you do, being a warrior. But here's where spells like Freeze come in handy - Freeze them, then rush in and hack away with your mana restoring weapon. I dare say there are other spells that will allow you to do similar things.
