I'm 15 and I'm loosing my will to live.

I'm tired all the time, hate everything about myself and don't really have anyone I feel safe talking to.
I feel betrayed because everyone who used to praise me and love me has strayed from me since I've become depressed, and what's worse is that nobody really seems to pick up on it since they've already gotten used to it.
I have no phyciatrist, no medication and have guardians I can no longer trust with personal feelings due to incriminating circumstances.
I've also found that I've become addicted to my own pain and suffering and am actually beginning to screw myself over (so I guess now I'm probably not even sane).

To correct this:

I've tried bettering myself through meditation and the ways of Tibetan Buddism.
I've gone through tough circumstances to improve my will power (fasting, endurance training, etc.)
I've gotten myself to be happy (or at least fake it) and make connections again, only to loose them when I regained my depression.
I've tried bettering myself physically through a gym membership and better exercise regemines.
I've become a vegetarien so that I could feel better about myself and improve spiritually and physically.
I've travelled to places by my own accord so that I can feel a better sense of achievement.
I've tried letting go of my worries and doubts and relaxing.
I've tried taking up hobbies and setting up goals to work relentlessly toward.

But none of it is working.

Am I screwed?