Get a Life, Chloe Brown (by Talia Hibbert)

This qualifies as a "fat-positive romance" for the Read Harder Challenge, but since I've already fulfilled that category, it also fits in "Read a book featuring a beloved pet where the pet doesn’t die." (The main character also has fibromyalgia, which is represented really well, which is where I thought this would slot in, but apparently I misremembered one of the categories.) 

This book is funny and charming and sexy; actually, maybe a little too sexy. There is a lot of very explicit sex and it somehow felt like a bit too much, too soon. But I loved the alternating points of view, the authentic emotional journeys each character was on, and the matter-of-fact and very positive handling of both body size and disability. 

You'd have to be really okay with a whole lot of non-euphemistic sex scenes, but if that's you, it's very worth reading. Also, the pet doesn't die!