Well, why not start over as a Breton Atronach? The difference in experience should take a way some of the pain of going through the beginning twice. The nice thing about a Breton Thief/Mage is that you have the extra magicka and magicka resistance right from the start. Plus the magic bonus points are enough to make magic useful even at level one. Of course your thief skills will start low but you can take stealth specialty to help that.
I'm becomming increasingly amazed at the lengths the devs went to cripple magic in this game. Take this for example. Obtaining a new grand soul gem and loading it with a Golden Saint, I try to figure out what I might do with it to enchant my glass helmet (which has 15 pts capacity) with a constant effect. I find I can fortify an attribute by 3 pts, shield 1pt or resist magic by 1 pt. Abandoning that idea as hardly worth it, I look at the possibilites on cast when used options. I find I can fortify magicka 50 pts for 6 seconds with it. That sounds a bit more useful. So I try this out and sure enough my magicka goes up from 111 to 161. Great, I think. So I cast 150 odd worth of spells, the bonus wears off so I have no more magicka left. OK, I use the helmet again, and I get about 10 pts on my magicka meter, not the expected 50. Wha'appen here? Well it seems they have implemented deficit accounting i.e. if you have a base magika pool of 100, fortify it by 50 and cast 150 pts worth of spells, when the fortify wears off your magicka pool is not 0 but negative 50. Which means you have to rest the extra hours or drink the extra potions to get the deficit back before you accrue any usable magicka at all. Which makes this enachantment off marginal use at best in a single battle but useless for clearing a dungeon.
Looking into this further, I happen to have two daedric katanas, one of which I have enchanted using a grand soul gem with 25-75% weakness to fire for 1 sec and 20 - 50 pts fire damage for 1 sec. This weapon is so awsomely powerfull I don't actually use it otherwise I wouldn't increase my long blade, block or light armour skills at any sort of rate. However the point is it has a change capacity of 400 and this enchantment costs 10 pts per strike which gives me 40 hits. The casting cost of the exact same spell from a spellmaker is 28 (on touch, target would cost more) which means that to reproduce the 40 casts over a dungeon clearance would require a magicka pool of 1120. When I consider that the weapon actually recharges, that a base magicka pool of over 1000 must be all but unattainable in this game anyway, and if that wasn't enough the sword operates on a no strike no fee basis, I conclude that a character using offensive magic is at such a massive disadvantage against one who simply whacks 'em with weapon that the only reason to play one would be to give yourself an extremely difficult challenge (assuming equal difficulty levels) with the additional hassle of worrying all the time about magicka and constantly having to fiddle with the spell menu during the action.
Anyway the upshot is I have two fully loaded grand soul gems and about 10 greaters and I can't even figure out what to do with them meaningfully after realising all this. Magic in Morrowind, it seems, holds a strictly support only role (healing, flying, water walking etc) except for weapon enchanting. I can't even use chameleon for fighting because they all just run away and it takes forever to chase them down.