1. I was in a similar state, and found out I had hyperthyroidism. Thyroid now removed, I'm much better, but there are many other such conditions that can be causing things that you might not have all the tools yourself to work out, so check with a doctor or your school's nurse at the very least.
2. Caffeine screws most people I know up. It's very fun and useful, and I don't recognize myself without it because I drank soda from a very early age, but this all could be contributing.
3. A lot of what you describe isn't too terribly bad, honestly, I mean, you need downtime, you are in college which is a hell of a lot of work.
4. The net makes you think you're terribly non-productive. Every single awesome throw-away link is some 10,000 man hours at the very least. I think we're all, in the tech world at least, trying to cope with this to varying degrees.
5. I highly recommend a counselor. Having a mostly unbiased third party is an amazing asset.
6. My big problem is not so much that I don't want to go out, just that I don't want to change what I'm doing, or I don't want to transition to the next thing. I highly recommend forcing yourself to get over that hump, and to go out and meet new people. Ask them questions. You'll hate it because they don't read the same feeds as you do, but you'll absolutely love it because if you hadn't done it, you would've never had had such a great time discovering what those people are all about. At the very least it is a great distraction, but often, people are a lot cooler than you may think.
Best of luck! You can do it!!!