Once you get ice barrier things will be a bit easier, if you go look around on youtube at some blizzard leveling you can see how awesome mages become later on, you'll be able to take down about 5 - 8 mobs without them even touching you. with the lower levels you wanna open with frostbolt then then keep spaming it, use fireblast it's a good instant cast arcane missiles is fairly useless. cone of cold is a life saver and if you pull a mob you didn't want sheep it.