I was in a really unhealthy and obsessive(both ways) relationship for 5 years. We had a lot of really insane fights and break ups. I think there is some kind of love addiction or codependency issue on both our parts. 

We stayed friends, sorta, he insisted on staying in my life because he felt like he could help me. Things like making sure I get up in the morning, ate etc. We had a big argument and now he doesnt want to talk anymore. 

He wants to move on and wants me to find someone else to love and take care of me. I don't want that. I understand that we can't be together as a couple, we're not healthy enough and there is too much painful history there for him.  But he wants to date new people and feels like he can't because I'll find out and go crazy. He says the type of relationship we have now revolves around tiptoeing around my feelings. He still loves me. He used to tell me that I was the only person he ever felt this way about, and probably wouldn't have that feeling again. He said he might date someone for companionship, and just tell them whatever they wanted to hear. Now he is saying that it won't be so black and white, and that his feelings might change.

This is the most terrifying thing in the world to me. I honestly cannot think of something more painful than this. Before I could cope with the fact that he was fucking a lot of other people and we would only be friends. Because it didnt actually mean the same as what we had. But now he is going to replace me. My only job was to love him and make him happy, and I fucked it up. He WANTS to replace me. I feel like I dont have a purpose and no longer need to exist.  When I think about him being with someone else in the same way as he was with me, I dont feel happy for him. I feel like throwing up.  I want to die, or for that person to die so he can feel what Im experiencing.

I realize fully that all of this isn't rational, and obsessive and weird. Someone else would be able to get on with their life. I can't think about sex without tearing up and feeling sick. He keeps telling me to date someone, but I don't want to leave my house, I hate dating, and I can't feel attracted to anyone else. 

I don't have any serious plans regarding suicide, but I dont trust the mood swings I'm having. I don't think I would kill myself, because I love my pets and would worry about what would happen to them. I just don't want to feel like this anymore. If he finds someone else, and its the same as we had, I feel that I am going to die. Maybe not on purpose, but that it is a life or death situation to me. 

Edit: In my mind, its like if he cuts off contact, and finds someone else to love, it will be as though he has died. I will mourn the same as if he did. The worst part is that he *wants* this to happen because I'm not good enough.