I have created a curated list of 500 self help books: https://selfhelp.glideapp.io/. It covers 35+ categories like assertiveness/ procrastination/ happiness/ spirituality/ stress & anxiety/ smoking cessation/ sexuality / career development/ parenting/ love/ marriage/ living with long-term conditions/ aging/ death, etc, etc.
Each category has a few recommended books with their Amazon ratings and a link to the book on Amazon. Coincidentally, most, if not all, have a digital version. Most are written by psychologists.
Hopefully, you will find something that makes a lasting impression on you too. Let me know your thoughts!