Desperate

When 19 year old Lucile Fairbourn goes to the prince's engagement ceremony, she locks eyes with him, and realizes he's her soulmate. But they can't ever be together. He's the rising king. She's poor, and can barely feed herself. Prince Xander takes her under his wing, and gives her everything she could ever need. But all she really wants is him

(This is a YA fantasy romance. The MMC is protective, cold, morally grey. And he'll do anything to protect her)