[foal]

Married people tend to be happier. On average.
Unfortunately one can't just walk down to the store and purchase an intimate relationship. But it could be something to work towards.

Once I finish school I'm going to pursue a career in non-profit work, because while the pay isn't high I think I'd be happier feeling like my work had some meaning to it. You could consider volunteering for a charity or cause. You may not feel strongly about any such things at the moment, but with a little research I'm sure you could fire yourself up a bit. Plus you'd meet new people and it may be the case that your current social relationships aren't wholly satisfactory.

Pay attention to diet and exercise. If everything fails you could try medication.

It doesn't sound to me like a hobby is what you need. I mean if something like poker is all you live for then the losses/downswings will really hit you hard. I generally don't allow myself to play when I'm depressed.