Elemental Exchange

You tear your foes apart with elemental power, and absorb the released energy to heal your own wounds. As part of this spell choose either acid, cold, fire, lightning, poison, or thunder damage. Make a melee spell attack against a creature within your reach. On a hit, the target takes 2d8 damage of your chosen type, and you regain hit points equal to the amount of damage dealt. Until the spell ends, you can make the attack again on each of your turns as an action.
If you use the Quickened Spell Metamagic option on this spell, you can make all subsequent attacks with this spell as a bonus action. If you choose to do so, then the healing you receive from this spell on these subsequent attacks is halved.
At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for each slot level above 3rd.