Those are worthy lessons, that too few realize too late. I also have been where you are - on the edge of a cliff about to leap. Life is cruel, and most people more so. The hard lesson is that life is a war - every day a battle to survive. Don't succumb to the darkness. Never give in, never surrender, ever. Find the fight deep within and forge a soul that is stronger from your trials. Find the good people in the world, those that care, who are gentle and kind. They can help rebuild your confidence and give you direction. The lessons they teach can forge you into a similar soul. You and the world will be better for it.

"The World Jones Made" by Philip K. Dick. Like much of his work it feels depressing and melancholy, however there is one paragraph, just one, that turns the story on its head. It is so thoroughly provocative and mind-bending that it made me re-evaluate my perspective on reality. A very Philip K. Dick thing to do.