I want to second the advice to write. That helps me a lot. Pick any of your hundreds of interest or articles. Reserve some time for it, lets say one hour. Study / read for 30-40 mins. And then use the rest of the time to write a summary. That is the hard part and forces you to concentrate and really understand the subject. It also clears out a lot of subjects because you will notice much faster what you are really interested in. Ideally blog about it so you have the pressure to write something decent.
What has helped me in that past is this here: "do nothing alternative"[1]. That is, I select a task that I think is most important to me and set aside a certain time to do it (lets say 2 hours). During that time I either work on that task or I do nothing. So if I don't want to work, fine. All I can do then is stare at the wall.
This has to effects: 1. I calm down. Its kind of an enforced meditation period. 2. I usually get bored and go back to the task.