The Gentleman’s Miscalculation by Laura Beers

Lord Winston Lockwood is haunted by his past and bound by social expectations. He remains at Brockhall Manor to ensure his aunt and her son remain safe from her abusive husband. Adding to his frustration, Miss Bawden’s constant presence threatens to drive him mad.
Amid the upheaval of her father’s newfound title, Miss Mattie Bawden is struggling to help her cousin cope with the tragic loss of her parents. Desperate for assistance, she turns to the last person she would ever expect: the insufferable Lord Winston.
As they call a truce, they soon realize how indubitably well-suited they are as friends. But when a dire threat looms, bringing danger to their very doorsteps, Winston understands he must confront his own feelings and risk revealing his true emotions, or he could lose the woman he has come to realize he cannot live without.