[Serious] Depression

[Nanoha Takamachi]

This should be self-evident, but my first and foremost suggestion for these sorts of situations are that if you aren't seeing a mental health professional already, I'd highly recommend considering it. A councillor, psychologist or the like will be able to properly assess if you should see a psychiatrist and, then, be prescribed any sort of medication. As folks here have already noted, medication can be pretty bad for you if you're taking the wrong stuff, too much of it, or mixing it with stuff you shouldn't. Don't at all consider taking anything without proper professional advice.

All that said, I'd really recommend seeing a professional psych or councillor, assuming you aren't already (in which case, keep seeing them unless you feel they aren't getting you the results you need, and then you need to look for someone else). I've been seeing the same psychologist for about 12 years now, and just being able to go see him (not very often at all now) has been pretty invaluable to me over the years. Rather than just being someone to talk to, they're also people who have a huge weight of knowledge and experience in talking to people with similar problems, and have access to huge amounts of associated information that can be used to help you out. Finding someone who suits you and you enjoy talking with is really crucial, though, so keep looking til you find someone you're happy with.

So, with my typical see a professional advice out of the way, I'd totally back up Greg on his whole finding a longer-term goal in life sounds like something that could really help you out. It needs to be some solid, concrete, challenging and also engaging. I'd be surprised if you find something that works right away, but that's just life I suppose. Keep trying new things, keep looking into different projects or goal or what have you. Keeping busy is the best way to avoid stagnation, and over time you'll find yourself working on longer-term stuff you're actually really interested in, and that more often that not leads to a pretty good time.