I had been in a relationship for a year when I was put in this position. I tried desperately for 2-years to make it work but couldn't: I didn't know how to handle the suicide attempts, he would nit-pick over everything to the point where every conversation would end in an argument even if it was totally pointless because he couldn't let anything go and always had to win even when he was being ridiculous, however diplomatic I tried to be, I was constantly made to feel terrible about myself even though I done nothing wrong, I couldn't talk about my own problems, he would insult me, my family, my ideals without even realising how hurtful what he was saying was, he was frightening when he got angry - it was truly awful by the end and I was so sad to end it because I love him so much but I just couldn't do it any more because it was destroying me.
I still love the person I fell in love with so much that its months after we broke up and I still cry myself to sleep each night, but he isn't really that person any more and I don't know if he will be again and I can't stay with him forever hoping that he will be. It had got to the point where I had to get out or would probably end up marrying him.
It's very easy to say you'll stay, but trust me, I stayed for a long time and it was not easy, and breaking up is not easy either.
The sad thig is that I think if someone had offered me help when they offered him out, or if we hadn't been so far away then it might have worked out ok.