Actually, that reminds me of the time that I took my brother's meds by accident before (I took medication for acne, but one day I took the wrong thing). I was so happy and social, I was thinking "WTF? Why am I so happy while at school?" Of course, it eventually wore off and I went down again, and I came to the conclusion that it must have been the meds.

I've never heard of Jesse Cox before. I've watched some let's plays, mainly in the languages that I'm learning.

A few things that help me:

Regular Exercise: I find giving myself a regimen really helps. Doesn't need to be rigorous necessarily, even a 20 minute jog a few times a week can help you feel better, though I personally recommend setting a routine that keeps you busy.

Projects/Goals: This is a weird thing to say on a gaming forum, but don't spend your days off gaming and doing nothing else. Set random goals for yourself. Something like: No games until I clean the house, no TV until I complete 10 job applications, etc. I did this a few years back when I was in between jobs, and it really helps keep your spirits up, even when you might feel like you're in a bad spot.

Routine Swap - Take a new route to work/school, eat somewhere or something new, etc. Changing your daily routine does a great job keeping you from getting complacent, which can lead to depression.

Adopt a pet! - Sounds silly, but looking after another life really changes your outlook. 

Reconnect with friends - This might be easier said than done, but I've found that, no matter how alone I might feel, there are always people out there who care. Don't feel isolated just because you spend a lot of time online, some of my best friends I met on anime and gaming forums.

Hope at least one of these help. If none of these apply or are practical for you, refer to Vivster's post.

Drink a lot of whisky. Fall asleep. Wake up. Grab a brush and put a little makeup. Hide the scars to fade away the shakeup.

Thanks! I'll try some of them. 

Exercise is useful, either as a proper regular routine or even a few minutes of walking as a way to break up tasks. I myself make a point of eating lunch a few blocks away from work partially to have an excuse to spend some time walking. It barely qualifies as exercise, but it helps.

Medication should not be your first resort, or even your second or third. There are good reasons to take it, but it's sort of like Godzilla. If you want to call Godzilla for help, it's because the alternative to having Tokyo getting wrecked is THAT bad. Save it for chronic and severe problems.

One trick I've used before was intentionally getting songs stuck in my head. Stupid as it feels to say, appropriately chipper music can do a bit of good. Preferably something short or repetitive, so that it can keep on looping even when you're note conscious of it. I've had luck using the Intermezzo tune from Dragon Quest, even though I don't actually like that series.

Last, is like to encourage thinking about the present. It might seem like a good idea to contextualize what you're doing, but I've found that thinking about past preparations mostly fills one with doubts and regrets, while thinking about the future at stake creates nervous tension and dread. Focusing on the immediate present doesn't necessarily help in of itself, but does prevent other less desirable circumstances from occurring.

Normally, I just stop what I'm doing, take a moment to lay down, and empty my mind for a moment. Just try to relax. Then once I'm ready, I get back up and continue what I was doing. Sleep tends to take my stress away too. After a good night sleep, I feel fresh again.

Meditation drills can help. Sometimes we have so much information we don't sit down and just process it all.

Assign yourself a small, easy task to achieve. Getting through it may alleviate some anxiety, move on to something else achievable. Repeat until you are eventually tackling big stuff.

If you know anyone else going through it as well, talk to them. It helps to get it off your chest with people who have been though it too.

I've tried to take naps before, but I can never fall asleep.