Our system is designed to make people feel worthless and hopeless. Worthless, hopeless people buy drugs and useless objects in an effort to try and feel better. Our system makes lots of money selling drugs (legal and illegal) and useless objects to these people. The more of these kinds of people exist, the more money the system makes. The key to this is isolation through TV, internet/facebook, long work hours indoors under creepy flourescent lighting, suburban living, poor food quality, etc… And of course engendering selfishness through advertising and the idea that “you deserve it.” Humans are social animals and don’t do well in isolation. Your family group may not be large enough to fulfill your innate social needs. When we age it is easy to lose touch with friends as they move away to take jobs that pay better so that they can buy more things or bigger houses.
The good news is that you don’t have to participate. Reconnect with any friends you have lost contact with and make a solid effort to be more connected. Find a yoga group that you like and commit to going. It is not just mental, it can do wonders to improve your physical well being. Focus less on object-oriented or self-oriented goals (buying things, learning a skill) and more on group-oriented goals (joining a club or church, volunteering, etc…) Direct your focus outwards, not inwards. Depression is sometimes just extreme self-centeredness.
I went through similar feelings a few years ago. I took a trip by myself to a very poor country and spent a few weeks there. I felt a lot better when I got back and my outlook on life was much improved. While there I made a real effort to connect with both other travelers as well as the people who lived there. I realized that I had been living a very self-centered life prior to the trip and had frequently been a bit of an ass. I still might be, but at least now I think I am more aware of this.