The Matchmaker's Match by Nicole Flockman

The Matchmaker’s Match is the third in the A Man's Best Friend Romance* series and as good as the other two. Two struggling people, struggling with their lives and with each other, are just meant to be, destined and fated by a solitary night together that was supposed to be a one up. Meeting again, they are thrown together by circumstances of both pain and joy.
This is an engaging story of their struggles and of the cutest dog ever, Buster, who knows they all belong together.

* Blind Date Bet and Next Door Knight