Denial of Death by Earnest Becker
Everybody is Wrong About God by James Lindsay

I don't know if this really fits what you're after but, "The Five Love Languages" Is a really good read. It talks about what makes people feel loved and breaks it down into 5 categories. Knowing how to determine someone's principal love language has been a HUGE help in my dealing with people.

If you want to look deeper than the psychology of the mind, try anything by Steven pinker. Psychology is as vunerable to and dependent on the physical world as to the abstract.

Barking up the Wrong Tree by Eric Barker, life planning linked with what makes us happy and what works, superb book

Use your favorite search engine and check AT LEAST 3 entries for each question you have. If you'd like, read "The Naked Ape" by Desmond Morris - I think it's a good starting point. Be aware you're asking about a HUGE subject - you have a monstrous amount of reading ahead of you (and it's totally worth it).

Don't sweat the small stuff...
and it's all small stuff...