Just so you know I find myself in a similar state.
I think I'll take the advice to clean off my desk, it's good to start somewhere. You're right, you could be suffering from depression, I think I might be, but I'm not in any hurry to start popping antidepressants and would like to see what I can accomplish through lifestyle changes.
One thing that helps me is when I'm home to set a time where I can't turn on the tv or computer, maybe one or two hours, and be strict about it. It's amazing the things I get done in the house at that time and the ideas I have. Start small with 1 or 2 hours of no computer/tv and then eventually if you like you can move it to an entire evening without it. With no tv to distract you all evening you may find yourself getting bored enough
that you're motivated to really work on developing your social life.