l think you are depressed, and yes it can, go see a doctor about it before it get's worse. See a doctor soon, the longer you wait the worse it gets, and the worse it gets, the harder it is to see a doctor.
Chronic depression needs to be diagnosed and treated by a therapist. A case of the occasional bummed out feeling can be overcome. Don't isolate yourself. Volunteer at the local homeless shelter, soup line etc. Put your sadness in perspective.
depression sucks balls. But it is what it is. A warped and unhealthy view of life. I have it too and actually the life situation is rarely anything to do with it. Its just depression. Some days i feel great especially if i have been running lots and eating well. Other days i feel like the world has got it in for me.
When I was depressed I used to dream of the happy moments of my past but I never thought to re-live them. Try it
yes by getting busy