Sanguine mage

Blood mages are often shunned or avoided as their pursuits and methods are commonly seen as troublesome. They harness the latent power within the flesh and blood, must often their own. 

Crimson Casting

As a blood mage you gain access to the list of sanguine spells to add to your list of known spells.

You gain the ability to cast sanguine spells. Sanguine spells can only be cost with health and not spell slots.

Casting sanguine spells cost an amount of health equal to 3 x the level of the spell. Spells of 6th level and higher require 20, 30, 40, 50hp. (Attempts to cast multiple spells of these levels in a day doubles the cost each time.)

Arcane transfusion

As a bonus action you may expend a spell slot to heal yourself for 1d4 per level of the spell slot + spell casting modifier. 
The

is feature can be used a number of times equal to your proficiency bonus per long rest.

Unnatural recovery

This feature replaces your arcane recovery.

Whenever you would take a short rest and expend hit dice to recover health you may use d12s instead of your wizard hit dice. If you heal for an amount over your max health you increase your max health by that amount. This effect ends after your next rest or if you drop to zero hit pints.

Payed in blood

Once per long or short rest, you may have a willing creature you can touch pay the health cost to cast a sanguine spell. A spell cast this way cannot exceed half you maximum spell slot level rounded up.

Cornered Animal

-You become immune to fear, and the fear condition.

-Whenever you would be reduced to zero hit points by damage from a creature you may force the source to make a Constitution saving throw.  If they fail you heal for half the damage you would have taken instead, and they take the other half as necrotic damage.

-Once you use this feature you cannot do so again until the next dawn.