Pic of character: http://puu.sh/w3UG
Yeah, your gear needs a lot of upgrading. Your DPS is very low and you also have extremely low vitality. I'm a level 26 wizard and I have 1,200 hit points on Normal. No wonder you are getting pwned-- 200 hit points is just not going to cut it.
Just remember, for your items you always want intelligence and vitality boosters for the wizard.
Make sure to pick to get the best weapon you can find in terms of DPS. On your off-hand, you probably don't want to be using a shield...there are orbs and books made specifically for a wizard that usually have much better stats for wizards. Otherwise, get yourself the most powerful 2-hand weapon you can find.
Your first priority should be to go to the AH and buy the two handed weapon with the highest DPS (well, you dont have to take THE highest, taking an item with slightly lower but with otherwise good stats is great) available for a reasonable price (not more than 15000 gold).
If it has a socket then buy and put a ruby square it the socket. (I would recommend a socket, but it isn't required)
There are probably other items that need to be fixed, but this is what you should prioritize.
EDIT: and your skills are not that amazing.
Where are you dumping your AP to do damage?
I suggest that you take arcane orb on your left mouse button as your "AP dump".
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