Hi Poly,
Try clinical hypnotherapy? I believe part of what's tormenting you is your belief that you can't do anything about what you think.
You have a chain of obsessive, negative, self-loathing thoughts and you believe they're like rain, you can't stop them from running endlessly through your mind.
I believe that's not true. Actually, I know it is. But I didn't discover that until I was in my 50s.
You could find out about this. It is hope.
No matter how convinced you are of your formula (the specifics of Poly's childhood + this + that = no hope), you are intelligent and imaginative enough to know you could be wrong.
And intelligent enough to persist. If you investigate methods of literally changing your thoughts, and do the practice that is known to work (hopefully with a trained certified hypnotherapist) ... you will change that script.
You won't just save your life. You'll save your mind. And once you begin, you will get a breath of hope. And that keeps you going. And in time, you look back, and you see how disordered you were (in your hopelessness), and you are so very glad that you stayed alive.
I hope you will, Poly.
(If you are addicted to pornography, there is help for that. So many good human beings've had -- and be helped out of -- that addiction and are still good human beings. It's a strange set of forces, and absences, and cultural messages -- and they have overwhelmed many men. Even some women.)
If I guessed wrong about that, forgive me. But I though it was worth saying to you, just in case that's it, I do not devalue you for it. (I loathe the pornography industry but have no loathing for the humans who get stuck in it.)
Hops