The book "Enough: True Measures of Money, Business, and Life" by John Bogle (http://www.amazon.com/Enough-True-Measures-Money-Business/dp...) might be good for you. I read it years ago. He talks about "how destructive an obsession with financial success can be".

Maybe you could change your focus outwards. For 30 days, instead of focusing on how you could amass more money, you could focus on what you could do to help the most people. You would likely feel less depressed after that.

This reminds me of a poem mentioned in the book:

True story, Word of Honor: Joseph Heller, an important and funny writer now dead, and I were at a party given by a billionaire on Shelter island.

I said, “Joe, how does it make you feel to know that our host only yesterday may have made more money than your novel ‘Catch-22′ has earned in its entire history?” And Joe said, “I’ve got something he can never have.” And I said, “What on earth could that be, Joe?” And Joe said, “The knowledge that I’ve got enough.” Not bad! Rest in peace!