First of all, have a read of this post.
Addiction – The First Step | Action Podcast
where someone forced herself to face the fact she was an addict of WoW (for several years!) and became an addict when it became more fulfilling than her real life. She only faced up to this a couple of weeks ago.
Secondly, lots of people get the blues in the third year of any course - I did several times on various degrees etc.. - it was getting 63% in an exam on one course that I had never got less than 82% for before that gave me the wake-up call I needed.
Thirdly, write a list of 5 simple things you can change each day, maybe what you eat for breakfast, where you buy your groceries, the route you take to school/work, whatever.
Fourthly, write 5 things in your life that you were/are successful at - even if its as 'silly' as breathing in and out every day or managing to get your jeans on the right way round each time!
If you are feeling down are you hanging around in your pjs? fling open the windows, take a shower every morning and put fresh clothes on.
You don't mention doing any physical exercise, if you're not, just take yourself off on a short walk every day - just 10 minutes up the road, turn round and back. Don't use an Ipod or anything, just walk, just listen to the stream of thoughts but without judging or criticizing them.
Here's an exercise that I find really helpful with many of my stuck clients in a coaching context:
Think of 6 instances in your life where you have done something, anything, YOU are proud of. It doesn't matter if anyone else knows, it doesn't matter if anyone else agrees, it doesn't matter if its 'really stupid'. Just 6 things in your life that gave you a little glow of pride.
Then write the stories around what happened and try to identify the things you did which made you proud and why. One of my instances involves a time when I made a decision at work of which I am still immensely proud and I would do again in a flash but which I got a complete b**king for off my boss!
If you seriously can't find 6, then set about setting up little stories for yourself - help the old lady across the road, ask the crying stranger if they are ok, whatever..