There's been a number of research studies that have looked into the effect of big lottery wins on happiness. The consistent result on all these studies is that a sudden surge of money does make people happier, but only for about a year to 18 months. After that they revert to the level of happiness they had before.
So while money and material goods do have an effect it's not lasting. Which rather reminds me of shopping: a smaller reward and the happy effect lasts for a corresponding shorter time.
So I believe that looking to material things as either an explanation for unhappiness, or as a potential cure, is not a solution.
Reading through some of GS's posts does make me think about times when I've been in positions where logic seemed to be dictating my entire life. The logic was I should remain in a certain job because I needed the money; that I shouldn't move; that I should continue studying; that I shouldn't devote more time to X Y or Z etc. Even though all these things together added up to an overall situation I didn't like, I felt constrained that they were all, individually, the "right" things to be doing.
But if all these things were "right" then why was I so dissatisfied ?
So the first time I went against this "logic of right things" it was nerve-wracking. I felt I was doing something stupid, even though it was what I really wanted to do. But within hours that gave way to relief and then happiness. Despite the fact that looked at from a logical point of view it was a stupid thing to do, I felt better, more optimistic and more "dynamic".
I was making decisions again based on what I really wanted rather than being carried along by the "logical choice".
And once you start making decisions you start going down new paths and much greater things can open up which you couldn't possibility have predicted.