Help?
I spent my youth plagued by do nothingness and moodiness too. I focused on understanding my own emotional barometer. I journaled a lot and I graphed my moods from day to day taking notes on it about any out of the ordinary events that day that may have related to my mood. This is going to sound weird but hey what can I say it's worth a shot and it's easy to do and it oddly enough works for me ...eat raisin bran. At least one bowl a day...it has betaine which helps build the natural insulation in the nerves, Tryptophan is also important and no you don't need a turkey...mozzarella cheese is the way to go for it , tryptophan can reverse depression. What have you got to loose? Eat a bowl of raisin bran and after about 30 minutes take notice of any change in your mental mood.
On an immediate level, sugar boosts your mood too- although for the long run, it's really important to keep to whole fruit instead of sweets. Oatmeal and st. John's wort are also supposed to be good for depression.
For me, three things really helped. One was to form my schedule as much as possible around things I was really, honestly interested in. Two, exercise. . . absurd amounts of exercise. Yay for endorphins. Find something you like- hiking and dancing were good for me- and start slow, building up. It makes a world of difference. Item three is the hardest- if there's anything about how you've been running your life that just feels wrong, pay attention to it and make a change, even if it seems impossible. For me it was moving several thousand miles to avoid someone I thought was my best friend. Painful, but worth it.
Lastly, you might consider the possibility that your depression- and the ensuing apathy- are fully justified. When I was in high school, I dealt with significant sexual harassment on a frequent basis; I would go for weeks without really speaking to my parents- because they didn't bother- and when the school called home about the fact that I hadn't stopped crying for three days, no one did anything about it. This is a small sample of the reasons I think my "illness" was, perhaps, the only reasonable reaction to my life.
Consider your life; chances are you have little opportunity to make your own choices, and few reasons to really believe in a genuine hope for the kind of future you would want to have. Furthermore, it's pretty disgusting of mainstream phychology to label it as diseased when someone refused to adjust to all of the sickness in this world, from genocide on Sudan to homelessness in your home town. If this is the real problem, this, perhaps, is what should be worked on; possibly a healthy dose of self determination, hope, and respect of your own distaste for distasteful things will release you from apathy.
Just some thoughts.