I'm 43 and have been experience similar conditions all my life. Counseling has shown that much of it stems from Post Traumatic Stress Disorder - of the traumas of the emotion neglect and abuse I suffered as a child and the consequent discovery of multiple personalities.
In recent years I had two major psychoses one a year after the other and what I feel was a religious experience although now it seems I'm a full blown paranoid schizophrenic.
I can't offer much hope only to say that with introspection comes understanding and insight and a learning how to deal with it all. That the self-harm diminishes and the scars fade.
For a long while I was taking a combination of an anti-convulsant and valium and that worked for a long time until I started hearing voices. Now I take anti-psychotics and an anti-depressant and Valium. I say this because our drug names are different in Australia.
Try keeping a journal - sometimes this can help.