This Could Change Everything by Jill Mansell (2018)

As I've said a million times, I love Jill Mansell because you don't know which of the players will end up together. Plus, such lovely rich characters. 

The book kicks off with Essie having a joke round robin letter sent to her entire address book, which results in her beau ditching her and getting fired (by beau's mother). But she soon finds a home with extravagant character Zillah and finding a job in a nearby bar, run by a very handsome Lucas. Much entanglement and complication ensues until everyone ends up with the right person. V. sweet.