Question for you: Why do you want to stay in a relationship that is hot and cold, emotionally unstable and that switches from good to awful? IF he is asking to break up, and is blackmailing you, why don't you give him what he wants and break up?

Emotional blackmail and threats like that are a form of emotional abuse. Do you really want to keep experiencing this? Seems to me like you're holding onto the good parts of the relationship without REALLY looking at how the bad parts are effecting your own mental health. If you've almost ended up in the hospital several times, this is NOT a healthy relationship for you. You've got to get honest with yourself here and see things for as they are.

I don't mean to sound harsh, just being upfront. This is not stable. ((((Hugs)))))