A Healing Cantrip

After seeing someone else atempt at making a healing cantrip, I though I would give it a go myself. Healing is a resource so you should not be able to heal however much you want, but sometimes only a little healing is required. So what I did was to make a necrotic healing spell, transfering your own life essence to someone else. I made the ratio of transfered to given HP really bad so that this cannot be done for eternity. I made this for Clerics but due to the nature of the spell, Warlocks should perhaps get it as well.

Sacrificial Aid

Necromancy Cantrip

Casting Time: 1 action

Range: Touch

Components: V

Duration: Instanttaneous

You touch a creature and sacrifce your own life essence to restore theirs. A creature you touch regains a number of hit points equal to 1d4, and you lose an amount of hit points equal to twice as much as you restored.

If you lose more hit points than you have left, the amount of excees hit points you otherwise would have lost is the amount your hit point maxium is decreased by until you finish a long rest.

The amount of hit points you can restore increases by 1d4 when you reach 5th level (2d4), 11th level (3d4), and 17th level (4d4).