I'm a Death student, too (level 17 to be exact) and I have around 870 health. I'm pretty sure that since Necromancers have spells that both damage their enemies and heal themselves, we don't necessarily need a huge amount of hit points (like Ice wizards) because we can just gain those points back in battle anyway. Personally, I go for clothes that provide more mana instead of health, but lots of people do the opposite for better stats. Anyway, I just wanted you to know that you're not the only Death wizard with low health. : )
Every school has its advantages and disadvantages, young Wizards, and these apply to the amount of health that you have as a Wizard.
Fire has medium health, low accuracy and high damage. Ice has the highest health, medium accuracy and low damage. Storm has the lowest health, the lowest accuracy and the highest damage. Life has high health, the highest accuracy and the lowest damage Death has low health, high accuracy and low damage. Myth has medium health, medium accuracy and medium damage. Balance has medium health, high accuracy and medium damage.