heartsmith

Opposite of heart breaker. From the comic made by Miyuli on tumblr, titled, "Hearts for Sale". Someone who shows affection and love, always giving their heart to everyone else. They give unconditional to anyone and help the heartbroken find their heart again by giving them a piece of a theirs. Until death.
The reason why they're called heartsmith is because it refers to blacksmith instead where the person mends hearts.