I hope we both agree that you're doing this to yourself. Thus, the only one who will able to bring you back out of this mental situation is yourself. From reading that post, i seem to think that the things that have happened to you seem to have created a sense of paranoia and that in itself creates a barrier in your head. You stop believing that you can be helped and the barrier is enforced in your brain everytime you think about it. The way forward is for YOU to remove that barrier and either try to fix the problem inside that wall or allow others to help you fix it.
Considering your current state, it may be hard to do what i'm about to suggest but it is worth trying and i believe you will be able to pull through. From your posts, i can tell that you are able to imagine the exteme, which is bad if the imagination is bad for you, but will be good if you feel as strongly about positive thoughts as you do those negative ones. So what you must do:
Each time you imagine these fears, also imagine the alternative of what will happen. The easy way is to think of the OPPOSITE of what will happen. Instead of pulling out a knife to attack you, the person may have a flower hidden in their pocket to give to you. You may have had a bad past at the age of 13-16 but try thinking back before that of the good things you've had in life. Instead of thinking that the therapists will not be able to help you, IMAGINE what it would be like if they actually succeeded. You'd be eating, you'd be able to go out with family and friends again, you'd be laughing in the theatre...anything you'd want in an ideal happy life. Each time you think of the opposite of what you're thinking, write it down, read it outloud manytimes to yourself.
It starts with the initial effort, by coming here to share with us this, you show us that you do care of what will happen to you. Deep inside you are hoping that one of us will be able to help you. A part of YOU wants this torment to end and for you to recover. Let that part come out.