A Taste After Dark by Audrey Rush

A human who will do anything for her family.
A vampire who could change it all.
A promise that may tear them apart.

Straight-laced Millie Desmond has one goal: to save her brother from an incurable disease, even if that means stealing from drug dealers to pay for his treatment. But when a man with dark eyes saves her from harm, Millie contemplates her decision to swear off men. Her sole responsibility is her brother, and yet the mysterious Daren stirs her deepest desires. When he reveals his true form, Millie realizes her brother’s life can be longer than ten short years—if she can convince Daren to break his promise.
For centuries, Daren Roberts has searched for complete solitude. But as the time to finally withdraw nears, his itch to hunt one last time gets him hooked on Amelia’s pure scent. As his arch-nemesis closes in on him, Daren knows Millie and her brother are in danger. He must protect them, and that means raging with his heart. Will he break his promise never to change another human? Will he save their lives?