Hunger by Gemma Brocato

Lia Thanos, Muse of Comedy, has joked her way through hundreds of lifetimes. But the past few months have been no laughing matter. She and her sisters have been locked in a battle to save Olympus from a hostile takeover. Now, the god challenging them has upped his game and personally selected the mortal man destined to help Lia win. Botanist Ben Jordan has his hands full; running a farmer’s market, helping his hearing-impaired sister, and trying to figure out why crops around the world are failing.

If the trend can’t be reversed, humans will starve and chaos will destroy the world. The only good news is the long-time famine he’s faced in his love life came to an end when he met Lia.
 Despite the fact that Ben finds it hard to believe immortal gods exist, he accepts the challenge to help Lia, a woman he yearns to spend the rest of his life with. But Pierus and his daughter, Hunger, will stop at nothing to keep the two apart.