What book should I read?

The thing that is most important for me right now is to: Resolve difficulties in life. Improve and increase ability. Gain more knowledge and further understanding

The difficulty I would need or like to address first is: Depression. Being unable to get over past losses. Repeating the same mistakes again and again. Personal Relationships Problems at work. Having happiness in my life.

The ability I wish to improve and increase the first is: Remembering what I read when I need to. Enhancing and creating desired personal relationships. Getting more done and achieving greater success. Taking my success to the next level. Finding happiness in life.

I want to know more and understand more about: The underlying principles of life, the mind, and the spirit. Myself. Why others act the way they do. The causes of mental illness, and what to do about them. How to reach my full potential.