This is the only thing that has worked for me and it worked fantastically:
1) Start with some Black Tea. In my experience the caffeine in black tea causes less of crash than coffee.
2) Hemmingways Hack: http://www.secondactive.com/2009/08/boost-your-productivity-...
3) And the Pomodoro Technique http://www.pomodorotechnique.com This has hemmingsways hack built in. If done right (read the PDF) it is amazing.
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As far as that last paragraph, it sounds like your depressed.
Depression is the most common mental health concern in our culture today. The main reason for this phenomenon is our dysfunctional lifestyle. We have stripped away supports such as family and community and replaced them with material objects, larger homes, entertainment centers, and more time at work for money and success, rather than interest, meaning, or passion. The lack of support, connectedness, and meaning leaves people feeling empty, lost, and depressed. These negatives feelings are symptoms trying to tell us that we're being deprived of essential human nutrients: to be seen, heard, and understood. Thus, depression is a healing crisis. -- http://www.wholenesstherapy.com/public/anxiety.htm
Like everyone else has said go see a counselor. You should be talking to some one about these feelings.
To me it sounds like you depression is stemming from a feeling of a lack control and a feeling that you don't have the power to make a change. If you can, I recommend reading this book http://www.amazon.com/Transformation-Understanding-Levels-Ma...