My Ogre Husband by Lyonne Riley

Maddie is one of only one hundred humans remaining, living behind the high walls of the New Eden preserve in order to protect her from the monsters that rule the world. Though Maddie longs for love, all her attempts at trial marriages have failed—leaving her wondering if she’s lovable enough to find her happily ever after.
Egorr the ogre wants a companion in life. When he applies for Maddie through the Human Companion program, they hit it off right away. Egorr is a gentle giant who adores Maddie’s good humor, and soon, they agree to a trial marriage.
But Egorr is big in more ways than one. When their first attempt at intimacy doesn’t go as planned, the two must figure out how to navigate love, sex, and marriage together. Can Maddie truly open her heart when she’s afraid of being hurt again?

This is a super steamy, low-angst, cozy monster romance (46k words) that features a plus-sized ogre MMC, a bubbly FMC, significant size difference, unintentional sexual injury, and a guaranteed HEA.