I recommend trying a website called Novelist, if your library subscribes to it (you should be able to search for it on your library website or just ask someone who works there). It allows you to input the moods and feels you want from a book and it will make suggestions. You can also get suggestions for similar books to those titles or authors you liked and often these are suggested by librarians and will include a little description of why they are similar.

Seconding talking to library staff! They are excellent at providing book ideas and suggestions, and have gone through training to be able to do this.