Start with high-confidence affirmations & mantras books, then narrow by subgenre or adjacent topics.
Touchstones
Anonymous
The Language of Letting Go
Melody Beattie
In God's Care
Karen Casey, Homer Pyle
Cornerstones
Victor La Cerva M.D., Victor La Cerva
Navigating Grief Workbook
Anna Darbonne PsyD
WORKING WITH THE LAW
Raymond Holliwell