This might help the secret writer: I was depressed, really to the point that I wanted to kill myself many years ago, but I made it out. I am not taking drugs anymore either. I'm not sure if it will help but your mind needs to focus on something that brings you joy. Look back into your childhood....what things were you doing then? For me, I had penpals, loads of them. I wrote to a different pen pal every day, and every day I would receive a letter in the mail. For me, that was my source of happiness, something to look forward to. Now I have the Secret Writer thing. It's also something I look forward to, something that takes my mind off of myself. Turning inwards too much is destructive. I recommend that you start to rediscover what things make you feel better, then do those things.
You can get better, I'm an example of that kind of recovery. I no longer want to die. I still get anxious, but I'm not obsessed with my own death anymore.
Oh, and just so you don't feel alone, I used to cut myself too. Not too much, but I did do it. Also, used to make my stomach hurt on purpose at work. I'd push myself into my desk in such a way that it jutted into my stomach, making me feel pain every day. I was addicted to hurting myself.
Honestly, what helped me the most was writing a book about these things. It took a lot of courage, but once I was done, and people who knew me read it, it was like, "Oh well, that's the real me. No more hiding, no more shame." My life sort of opened up at that moment because I was forced to take a hard look at what I had become.