You can find items that will boost your ice spells a bit, but the game is simply not going to give you full damage in all spectrums. Once you hit the high levels it gets tough to run without a rounded out group. Most quests start hitting with mobs made up of several type monsters, so you will be strong in one area and need help in another. I found it fun to figure out what worked best where on who. lol

Your build seems fine for your sorc. Just have fun, play with the ray spells and find out what will do most damage. DoT spells are good, you can hit them and retreat, then when you come back they are dead or at least limping. lol