It's called Leaving London and you can buy it on Amazon.
Here's the blurb:
For Lucille Glencross, career is everything and relationships are nothing. Having experienced a fractured childhood, she is convinced that the only route to happiness involves standing on her own two feet and trusting no one. In this way, she protects herself from further hurt.
But when her best friend invites her to be a bridesmaid in Italy, Lucille’s orderly world is turned upside down. Whilst meeting new people and observing different customs, Lucille begins to wonder whether she’s got it all wrong. Could there be another, happier way to live her life?