Dear Brokengirl,
The story you have told is one of the most horrifying, especially because you are a very young lady and seems you have a bonafide out of control, cruel and clearly dangerous loose cannon of a man in your life. None of us are qualified to diagnose psychopathy, but clearly this is man presents MORE than the average danger and what may be considered 'of the violent sort' and terribly destructive. When they talk about killing people or themselves I think they are MUCH more active, full of frustration, rage, and therefore present 'imminent' danger to anyone they are close to.
Mine is like that. Also, you will always hear about 'cancer' stories, broken bones, being locked out of the house or car, accidents, victimization all the time. He's really classic, but he's also not experienced, so he's all over the place. He slept with your best friend FFS? That's enough to dump a guy in the real world!
You really MUST eliminate ALL Contact, no matter what you THINK or FEEL at any time. Nothing Good is EVER going to come of any more contact you have with this person. You have only 10 months invested, cut your losses and RUN. You are much better off today than you will ever be. UNDERSTAND THAT FULLY! Today is your best day, and every day will be better than this one.
Understand something else. If you continue contact, EVERY DAY AFTER TODAY is going to GET WORSE. That is something I would bet my own life on.
What is your attachment to him after 10 months? NONE, ok? NONE. But think about this, if you 'continue' the damage can reflect on you for a long time.
You are young, and if you SAY NO NOW, it's likely you will be saying No to a lifetime of being abused. This is your Shining moment. (pun intended)
Get rid of this guy and come here for support. I will talk to you here if you need, every single day if you want.
You really reached me with this story, I think you are in a lot of trouble with this one. And being so young, it just breaks my heart.